Image formation device, development unit, and computer system

ABSTRACT

An image forming apparatus is provided with: a moving body provided with a plurality of attach/detach sections, wherein a developing unit is attachable to and detachable from each of the attach/detach sections, and the developing unit has a developer containing section and an element with which communication is possible; a photoconductor on which a latent image can be formed; and an antenna for wirelessly communicating with the element of the developing unit attached to the attach/detach section; wherein a longitudinal direction of the antenna is in a direction of movement of the moving body. Further, during a period from when the developing unit arrives at the opposing position until when it arrives at the detaching position due to movement of the moving body, a writing member writes information into the element of the developing unit.

TECHNICAL FIELD

The present invention relates to image forming apparatuses, developingunits, and computer systems.

BACKGROUND ART

Among image forming apparatuses such as laser beam printers, there arethose to and from which a developing unit having a memory can beattached and detached and that cause the developing unit, which has beenattached, to rotate using a rotating device such as a rotary so as toprint in full color a latent image formed on a photoconductor.

In some apparatuses, when the rotary is positioned at a predeterminedposition, the developing unit can be attached to and detached from themain body of the image forming apparatus via an attach/detach opening.

Communication is carried out between the memory and the main body of theimage forming apparatus so as to read and write various types ofinformation from and into the memory of the developing unit.

It is necessary that communication between the memory and the main bodyof the image forming apparatus is carried out properly. For example,when information regarding the remaining amount of toner is to bewritten into the memory of the developing unit, if a communication erroroccurs and incorrect information is written, then the remaining amountof toner in the developing unit cannot be managed properly.

The present invention has been made in light of the foregoing problem,and it is an object thereof to achieve image forming apparatuses,developing units, and computer systems with which communication can beaccurately carried out with respect to a developing unit, for example,having an element.

It is a further object of the present invention to achieve image formingapparatuses and computer systems with which information can beaccurately written into a developing unit, for example, having anelement.

DISCLOSURE OF INVENTION

To solve the foregoing problems, a main aspect of the present inventionis an image forming apparatus comprising: a moving body provided with aplurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of the attach/detach sections,and the developing unit has a developer containing section and anelement with which communication is possible; a photo conductor on whicha latent image can be formed; and an antenna for wirelesslycommunicating with the element of the developing unit attached to theattach/detach section; wherein a longitudinal direction of the antennais in a direction of movement of the moving body.

Another main aspect of the present invention is an image formingapparatus comprising: a moving body provided with a plurality ofattach/detach sections, wherein a developing unit is attachable to anddetachable from each of the attach/detach sections, and the developingunit has a developer containing section and an element into whichinformation can be written; a photoconductor on which a latent image canbe formed; a writing member for writing information into the element;and an attach/detach opening through which the developing unit isattached to and detached from the attach/detach section; wherein: in astate in which the developing unit is positioned at an opposing positionwhere the developing unit is in opposition to the photoconductor due tomovement of the moving body, development of the latent image with thedeveloper contained in the developing unit is possible; in a state inwhich the developing unit is positioned at a detaching position that isdifferent from the opposing position due to movement of the moving body,detachment of the developing unit from the attach/detach section via theattach/detach opening is possible; and during a period from when thedeveloping unit arrives at the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the writing member writes information into the element ofthe developing unit.

Features and objects of the present invention other than the above willbecome clear in accordance with the description of the presentspecification and the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram for describing how a developing unit 54 (51, 52, 53)and a photoconductor unit 75 are attached to and detached from a printerunit 10 a.

FIG. 2 is a diagram showing main structural components constituting theprinter 10.

FIG. 3 is a block diagram showing a control unit 100 provided in theprinter 10.

FIG. 4 is a perspective view of a yellow developing unit 54 seen fromthe perspective of a developing roller 510.

FIG. 5 is a cross-sectional diagram showing main structural componentsof the yellow developing unit 54.

FIG. 6A is a plan transparent view showing the structure of an element.

FIG. 6B is a block diagram for describing the internal configuration ofthe element and a send/receive section.

FIG. 7 is a diagram for describing the information stored in a memorycell 54 h of the memory 54 a.

FIG. 8 is a diagram for describing the information stored in a memorycell of the element 54 a of the photoconductor unit 75.

FIG. 9A is a diagram for describing the relationship between the elementand the printer-side antenna when the yellow developing unit 54 ispositioned at a developing position.

FIG. 9B is a diagram for describing the relationship between the elementand the printer-side antenna when the yellow developing unit 54 ispositioned at an attach/detach position.

FIG. 9C is a diagram for describing the relationship between the elementand the printer-side antenna when the rotary 55 is positioned at a homeposition.

FIG. 10 is a flowchart for describing how information is written intothe element of the developing unit.

FIG. 11 is a flowchart showing an example of how information is writteninto the element 75 a of the photoconductor unit 75.

FIG. 12 is a diagram showing a first alternative embodiment of theprinter-side antenna.

FIG. 13 is a diagram showing another embodiment regarding thearrangement of the elements.

FIG. 14 is a diagram showing a second alternative embodiment of theprinter-side antenna.

FIG. 15 is an explanatory diagram showing the external configuration ofa computer system.

FIG. 16 is a block diagram showing the configuration of the computersystem shown in FIG. 15.

A legend of the main reference characters used in the drawings isdescribed below.

-   10 printer-   10 a printer unit 10 a-   10 b first open/close cover-   10 c second open/close cover-   10 d photoconductor unit attach/detach opening-   10 e developing unit attach/detach opening-   20 photoconductor-   30 charging unit-   40 exposing unit-   50 YMCK device-   51 cyan developing unit-   52 magenta developing unit-   53 black developing unit-   54 yellow developing unit-   51 a, 52 a, 53 a, 54 a elements-   54 b noncontact IC chip-   54 c resonant capacitor-   54 d antenna-   54 e rectifier-   54 f signal analysis section RF-   54 g controller-   54 h memory cell-   55 rotary-   55 a central shaft-   55 b, 55 c, 55 d, 55 e attach/detach sections-   60 first transferring unit-   70 intermediate transferring body-   75 photoconductor unit-   75 a element-   76 cleaning blade-   76 a waste toner containing section-   80 second transferring unit-   90 fusing unit-   92 paper supply tray-   94 paper supply roller-   95 display unit-   96 resist roller-   100 control unit-   101 main controller-   102 unit controller-   112 interface-   113 image memory-   120 CPU-   121 serial interface-   122 printer-side memory (storage element)-   123 send/receive circuit-   124 a printer-side antenna (for communicating with photoconductor    unit element)-   124 b, 124 c, 124 d printer-side antennas (for communicating with    developing unit elements)-   125 YMCK developing device drive control circuit-   126 a AC voltage supply section-   126 b DC voltage supply section-   127 exposing unit drive control circuit-   127 a pixel counter-   510 developing roller (developer bearing roller)-   520 seal member-   524 seal urging member-   522 seal support metal plate-   530 first toner containing section-   535 second toner containing section-   540 housing-   541 opening-   545 restriction wall-   550 toner supply roller (toner supply member)-   560 restriction blade-   560 a rubber section-   560 b rubber support section-   562 blade support metal plate-   570 blade backing member-   1000 computer system-   1002 computer unit-   1104 display device-   1106 printer-   1108 input device-   1108A keyboard-   1108B mouse-   1110 reading device-   1110A flexible disk drive device-   1110B CR-ROM drive device-   1202 internal memory-   1204 hard disk drive unit-   T toner-   RS read sensor for synchronization

Best Mode For Carrying Out The Invention

At least the following matters will be made clear by the description ofthe present specification and the accompanying drawings.

An image forming apparatus comprises: a moving body provided with aplurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of the attach/detach sections,and the developing unit has a developer containing section and anelement with which communication is possible; a photoconductor on whicha latent image can be formed; and an antenna for wirelesslycommunicating with the element of the developing unit attached to theattach/detach section; wherein a longitudinal direction of the antennais in a direction of movement of the moving body.

With the foregoing image forming apparatus, the longitudinal directionof the antenna is in the direction of movement of the moving body, andthus, it is possible to effectively communicate wirelessly with theelements of developing units attached to the attach/detach sectionsprovided in the moving body.

Further, in the image forming apparatus, the moving body may moverotatively.

With the foregoing image forming apparatus, it is possible toeffectively communicate wirelessly with the elements of developing unitsattached to the attach/detach sections provided in the moving body,which moves rotatively.

Further, in the image forming apparatus, a length of the antenna in thelongitudinal direction may be longer than a length of the element in thelongitudinal direction.

With the foregoing image forming apparatus, since the length of theantenna in the longitudinal direction is longer than the length of theelement in that longitudinal direction, it is possible to wirelesslycommunicate more effectively with the elements of developing unitsattached to the attach/detach sections provided in the moving body.

Further, in the image forming apparatus, the antenna may be provided ata position that is in opposition to and extending over a firstdeveloping unit attached to a first attach/detach section and a seconddeveloping unit attached to a second attach/detach section that isadjacent to the first attach/detach section.

With the foregoing image forming apparatus, since the antenna isprovided at a position where it is in opposition to and extends overadjacent developing units, it is possible to wirelessly communicate moreeffectively with the elements of developing units attached to theattach/detach sections provided in the moving body.

Further, in the image forming apparatus, the antenna may be provided ata position that is in opposition to at least either one of a firstelement provided in/on the first developing unit or a second elementprovided in/on the second developing unit.

With the foregoing image forming apparatus, since the antenna isprovided at a position where it is in opposition to at least either oneof the elements of adjacent developing units, it is possible towirelessly communicate more effectively with the elements of developingunits attached to the attach/detach sections provided in the movingbody.

Further, in the image forming apparatus, the antenna may be providedmore to the outside than the element in a radial direction of rotationof the moving body.

With the foregoing image forming apparatus, an antenna which is providedmore to the outside than the element in the radial direction of rotationof the moving body can be used to wirelessly communicate moreeffectively with elements of developing units attached to theattach/detach sections provided in the moving body.

Further, in the image forming apparatus, the antenna may be providedmore to the outside than the element in a direction of a rotation axisof the moving body.

With the foregoing image forming apparatus, an antenna which is providedmore to the outside than the element in the direction of the rotationaxis of the moving body can be used to wirelessly communicate moreeffectively with elements of developing units attached to theattach/detach sections provided in the moving body.

Further, in the image forming apparatus, the antenna may be capable ofwirelessly communicating with the element of the developing unit that ismoving.

With the foregoing image forming apparatus, since the antenna canwirelessly communicate with elements of developing units that aremoving, the period during which the developing units are moving can beutilized to allow wireless communication with the elements.

Further, in the image forming apparatus, the antenna may be used towrite information wirelessly into the element of the developing unitthat is moving.

With the foregoing image forming apparatus, since the antenna is used towrite information wirelessly into elements of developing units that aremoving, the period during which the developing units are moving can beutilized to write information into elements effectively.

Further, in the image forming apparatus, the antenna may be capable ofcommunicating with the element in a non-contact state with respect tothe element.

With the foregoing image forming apparatus, it is possible tocommunicate, in a non-contact state, with the elements of developingunits attached to the attach/detach sections provided in the movingbody.

Further, in the image forming apparatus, the antenna may be used towrite, into the element, information indicating a remaining amount ofdeveloper contained in the developing unit provided with that element.

Since the amount of developer that is contained in a developing unitdecreases as developing is carried out, it is preferable that theremaining amount of developer is appropriately written into the element.Here, with the foregoing image forming apparatus, the antenna can beused to write information about the remaining amount.

Further, in the image forming apparatus, the antenna may write, into theelement, information indicating a usage amount of developer contained inthe developing unit provided with that element.

Since the amount of developer that is contained in a developing unitdecreases as developing is carried out, it is preferable that theremaining amount of developer is appropriately written into the element.Here, with the foregoing image forming apparatus, the antenna can beused to write information about the usage amount.

Further, in the image forming apparatus, the image forming apparatus maycomprise an AC voltage supply section for supplying an AC voltage; andduring a period from a start to an end of an image forming process, theimage forming apparatus may write information into the element of thedeveloping unit attached to the attach/detach section using the antennawhen the AC voltage supply section is not supplying an AC voltage.

If an AC voltage supply section for supplying an AC voltage is provided,then when the AC voltage supply section is supplying an AC voltage,there is a possibility that electromagnetic noise will be generated atits periphery.

With the foregoing image forming apparatus, the apparatus writesinformation into the element using the antenna when the AC voltagesupply section is not supplying an AC voltage during a period from thestart to the end of an image forming process, and thus information canbe written accurately without being affected by noise caused bysupplying the AC voltage, for example.

Further, in the image forming apparatus, the developing unit may have adeveloper bearing body for bearing developer; and the AC voltage supplysection may supply an AC voltage to the developer bearing body.

With the foregoing image forming apparatus, the apparatus writesinformation into the element using the antenna when the AC voltagesupply section is not supplying an AC voltage to the developer bearingbody during a period from the start to the end of an image formingprocess, and thus information can be written accurately without beingaffected by noise caused by supplying the AC voltage to the developerbearing body, for example.

Further, in the image forming apparatus, the image forming apparatus maycomprise a charging member for charging the photoconductor; and the ACvoltage supply section may supply an AC voltage to the charging member.

With the foregoing image forming apparatus, the apparatus writesinformation into the element using the antenna when the AC voltagesupply section is not supplying an AC voltage to the charging memberduring a period from the start to the end of an image forming process,and thus information can be written accurately without being affected bynoise caused by supplying the AC voltage to the charging member, forexample.

Further, in the image forming apparatus, the image forming apparatus maycomprise an attach/detach opening through which the developing unit isattached to and detached from the attach/detach section; in a state inwhich the developing unit is positioned at an opposing position wherethe developing unit is in opposition to the photoconductor due tomovement of the moving body, development of the latent image with thedeveloper contained in the developing unit may be possible; in a statein which the developing unit is positioned at a detaching position thatis different from the opposing position due to movement of the movingbody, detachment of the developing unit from the attach/detach sectionvia the attach/detach opening may be possible; and during a period fromwhen the developing unit arrives at the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the image forming apparatus may write information into theelement of the developing unit using the antenna.

If an attach/detach opening through which a developing unit is attachedto and detached from an attach/detach section is provided, there is apossibility that the developing unit attached to the attach/detachsection may inadvertently be detached via the attach/detach opening. Inparticular, since the amount of developer in a developing unit decreaseswhen that developing unit is positioned at the opposing position anddeveloping is carried out, if that developing unit is detached beforeinformation about the amount of developer that has been decreased iswritten into its element, it may not be possible to ascertain the amountof developer contained in the developing unit, for example.

Here, with the foregoing image forming apparatus, information about theremaining amount etc. of developer is written into the element of thedeveloping unit using the antenna during the period from when thedeveloping unit arrives at the opposing position until when it arrivesat the detaching position due to movement of the moving body. Therefore,even if the developing unit is detached via the attach/detach opening,information about the amount of developer contained in the developingunit, for example, is written accurately without being affected by noisecaused by supplying an AC voltage, for example.

Further, in the image forming apparatus, the difference between amaximum voltage value and a minimum voltage value of the AC voltage maybe 1000 volts or more.

When the difference between the maximum voltage value and the minimumvoltage value of the AC voltage is 1000 volts or more, theelectromagnetic noise that is generated also becomes large. With theforegoing image forming apparatus, information is written into theelement using the antenna when the AC voltage supply section is notsupplying an AC voltage during the period from the start to the end ofthe image forming process, and thus, information can be writtenaccurately without being affected by the large noise caused by supplyingthe AC voltage, for example.

It is also possible to achieve an image forming apparatus comprising: amoving body provided with a plurality of attach/detach sections, whereina developing unit is attachable to and detachable from each of theattach/detach sections, and the developing unit has a developercontaining section and an element with which communication is possible;a photoconductor on which a latent image can be formed; and an antennafor wirelessly communicating with the element of the developing unitattached to the attach/detach section, wherein: a longitudinal directionof the antenna is in a direction of movement of the moving body; themoving body moves rotatively; a length of the antenna in thelongitudinal direction is longer than a length of the element in thelongitudinal direction; the antenna is provided at a position that is inopposition to and extending over a first developing unit attached to afirst attach/detach section and a second developing unit attached to asecond attach/detach section that is adjacent to the first attach/detachsection; the antenna is provided at a position that is in opposition toat least either one of a first element provided in/on the firstdeveloping unit or a second element provided in/on the second developingunit; the antenna is capable of wirelessly communicating with theelement of the developing unit that is moving; the antenna is capable ofcommunicating with the element in a non-contact state with respect tothe element; and the antenna is used to write, into the element,information indicating a remaining amount or a usage amount of developercontained in the developing unit provided with that element.

It is also possible to achieve a developing unit comprising a developercontaining section, and an element with which communication is possible;wherein the developing unit is capable of being attached to and detachedfrom an attach/detach section of a main body of an image formingapparatus that includes: a moving body provided with a plurality of theattach/detach sections, the developing unit being attachable to anddetachable from one of the attach/detach sections; a photoconductor onwhich a latent image can be formed; and an antenna for wirelesslycommunicating with the element of the developing unit attached to theattach/detach section; and wherein a longitudinal direction of theelement is in a longitudinal direction of the antenna when thedeveloping unit is attached to the attach/detach section.

With the foregoing developing unit, the longitudinal direction of theelement is in the longitudinal direction of the antenna when thedeveloping unit is attached to the attach/detach section, and thus,effective wireless communication with the elements of developing unitscan be achieved.

Further, in the developing unit, the developing unit may be capable ofbeing attached to the attach/detach section of the moving body thatmoves rotatively.

The foregoing developing unit allows effective wireless communicationwith respect to an element of the developing unit attached to theattach/detach section of the moving body, which moves rotatively.

Further, in the developing unit, the length of the element in thelongitudinal direction may be shorter than the length of the antenna inthe longitudinal direction.

The foregoing developing unit allows more effective wirelesscommunication with respect to the element of the developing unitattached to the attach/detach section of the moving body because thelength of the element in the longitudinal direction is shorter than thelength of the antenna in the longitudinal direction.

Further, in the developing unit, the element may be capable ofcommunicating with the antenna in a non-contact state with respect tothe antenna.

The foregoing developing unit allows communication with respect to theantenna in a non-contact state.

Further, in the developing unit, the element may store informationindicating a remaining amount of developer contained in the developingunit provided with that element.

Since the amount of developer that is contained in the developing unitdecreases as developing is carried out, it is preferable that theremaining amount of developer is appropriately stored in the elements.Here, with the foregoing developing unit, it is possible to storeinformation about the remaining amount in the element.

Further, in the developing unit, the element may store informationindicating a usage amount of developer contained in the developing unitprovided with that element.

Since the amount of developer that is contained in the developing unitdecreases as developing is carried out, it is preferable that the usageamount of developer is appropriately stored in the elements. Here, withthe foregoing developing unit, it is possible to store information aboutthe usage amount in the element.

It is also possible to achieve a developing unit comprising: an elementwith which communication is possible using an antenna; and a developercontaining section for containing developer; wherein a longitudinaldirection of the antenna intersects with a longitudinal direction of thedeveloping unit.

For example, if the longitudinal direction of the element is in thelongitudinal direction of the antenna of a main body of an image formingapparatus when the developing unit is attached to the image formingapparatus main body, then it is possible to achieve effective wirelesscommunication with respect to the element of the developing unit.

It is also possible to achieve a computer system comprising: a computerunit; and an image forming apparatus that is connected to the computerunit and that includes a moving body provided with a plurality ofattach/detach sections, wherein a developing unit is attachable to anddetachable from each of the attach/detach sections, and the developingunit has a developer containing section and an element with whichcommunication is possible, a photo conductor on which a latent image canbe formed, and an antenna for wirelessly communicating with the elementof the developing unit attached to the attach/detach section; wherein alongitudinal direction of the antenna is in a direction of movement ofthe moving body.

An image forming apparatus comprises: a moving body provided with aplurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of the attach/detach sections,and the developing unit has a developer containing section and anelement into which information can be written; a photoconductor on whicha latent image can be formed; a writing member for writing informationinto the element; and an attach/detach opening through which thedeveloping unit is attached to and detached from the attach/detachsection; wherein in a state in which the developing unit is positionedat an opposing position where the developing unit is in opposition tothe photoconductor due to movement of the moving body, development ofthe latent image with the developer contained in the developing unit ispossible; wherein in a state in which the developing unit is positionedat a detaching position that is different from the opposing position dueto movement of the moving body, detachment of the developing unit fromthe attach/detach section via the attach/detach opening is possible; andwherein during a period from when the developing unit arrives at theopposing position until when the developing unit arrives at thedetaching position due to movement of the moving body, the writingmember writes information into the element of the developing unit.

In a configuration in which a developing unit, which has an element intowhich information can be written and a developer containing section, canbe attached to and detached from an attach/detach section, there is apossibility that the developing unit attached to the attach/detachsection may be inadvertently detached via the attach/detach opening. Inparticular, since the amount of developer in the developing unitdecreases when that developing unit is positioned at the opposingposition and developing is carried out, if that developing unit isdetached before information about the amount of developer that has beendecreased is written into its element, it may not be possible toascertain the amount of developer contained in the developing unit, forexample.

Here, with the foregoing image forming apparatus, the writing memberwrites information about the remaining amount etc. of developer into theelement of the developing unit during the period from when thedeveloping unit arrives at the opposing position until when it arrivesat the detaching position due to movement of the moving body. Therefore,even if the developing unit is detached via the attach/detach opening,information about the amount of developer contained in the developingunit, for example, can be ascertained properly.

Further, in the image forming apparatus, during a period from when adeveloper bearing body provided in the developing unit that has arrivedat the opposing position ends developing the latent image until when thedeveloping unit arrives at the detaching position, the writing membermay write information into the element of the developing unit.

The amount of developer in a developing unit decreases when the latentimage is developed by the developer bearing body provided in thatdeveloping unit. Here, with the foregoing image forming apparatus, thewriting member writes information into the element of the developingunit during the period from when the developer bearing body provided inthe developing unit that has arrived at the opposing position endsdeveloping the latent image until when that developing unit arrives atthe detaching position. Consequently, information about the remainingamount, for example, based on the amount of developer that has decreaseddue to development is written into the element of the developing unit.

Further, in the image forming apparatus, during a period from when thedeveloping unit starts moving from the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the writing member may write information into the elementof the developing unit.

With this image forming apparatus, the time from when the developingunit starts moving from the opposing position until when it arrives atthe detaching position can be utilized to write information effectively.

Further, in the image forming apparatus, if, during the period from whenthe developing unit starts moving from the opposing position until whenthe developing unit arrives at the detaching position, anotherdeveloping unit adjacent to the developing unit on the upstream sidetherefrom in a direction of movement of the moving body is to arrive atthe opposing position, then the writing member may write informationinto the element of the developing unit during a period until the otherdeveloping unit arrives at the opposing position.

With this image forming apparatus, the writing member writes informationinto the element of a developing unit before the other developing unitarrives at the opposing position, and thus, for example, even if thedeveloping unit is forcibly detached after the other developing unit hasarrived at the opposing position, information would already be writteninto its element.

Further, in the image forming apparatus, the image forming apparatus maycomprise an AC voltage supply section for supplying an AC voltage; andthe writing member may write information into the element of thedeveloping unit attached to the attach/detach section when the ACvoltage supply section is not supplying an AC voltage.

If an AC voltage supply section for supplying an AC voltage is provided,then when the AC voltage supply section is supplying an AC voltage,there is a possibility that electromagnetic noise will be generated atits periphery.

With the foregoing image forming apparatus, the writing member writesinformation into the element of the developing unit attached to theattach/detach section when the AC voltage supply section is notsupplying an AC voltage. Therefore, information can be writtenaccurately without being affected by noise caused by supplying the ACvoltage, for example.

Further, in the image forming apparatus, the developing unit may have adeveloper bearing body for bearing developer; and the AC voltage supplysection may supply an AC voltage to the developer bearing body.

With this image forming apparatus, the writing member writes informationinto the element of a developing unit attached to an attach/detachsection when the AC voltage supply section is not supplying an ACvoltage to the developer bearing body, and thus information can bewritten accurately without being affected by noise caused by the supplyof AC voltage to the developer bearing body, for example.

Further, in the image forming apparatus, the image forming apparatus maycomprise a charging member for charging the photoconductor; and the ACvoltage supply section may supply an AC voltage to the charging member.

With this image forming apparatus, the writing member writes informationinto the element of a developing unit attached to an attach/detachsection when the AC voltage supply section is not supplying AC voltageto the charging member, and thus information can be written accuratelywithout being affected by noise caused by the supply of AC voltage tothe charging member, for example.

Further, in the image forming apparatus, the writing member may writeinformation into the element in a non-contact state with respect to theelement.

With this image forming apparatus, the writing member writes informationto the element in a non-contact state with respect to the element, andthus information can be written to the element even if the developingunit is moving.

Further, in the image forming apparatus, a difference between a maximumvoltage value and a minimum voltage value of the AC voltage may be 1000volts or more.

When the difference between the maximum voltage value and the minimumvoltage value of the AC voltage is 1000 volts or more, theelectromagnetic noise that is generated also becomes large. With theforegoing image forming apparatus, the writing member writes informationto the element of the developing unit that is attached to theattach/detach section when the AC voltage supply section is notsupplying AC voltage, and thus information can be written accuratelywithout being affected by, for example, the large noise caused by thesupply of AC voltage.

Further, in the image forming apparatus, the writing member may write,into the element, information indicating a remaining amount of developercontained in the developing unit provided with the element.

Since the amount of developer that is contained in the developing unitdecreases as developing is carried out, it is preferable that the amountof remaining developer is appropriately written to the elements. Here,with the foregoing image forming apparatus, the writing member writesinformation indicating the remaining amount of the developer to theelement of a developing unit during the period after that developingunit arrives at the opposing position until it arrives at the detachingposition due to movement of the moving body, and thus even if thedeveloping unit is detached via the attach/detach opening, the remainingamount of developer contained in the developing unit can be accuratelyascertained.

Further, in the image forming apparatus, the writing member may write,into the element, information indicating a usage amount of developercontained in the developing unit provided with the element.

Since the amount of developer that is contained in the developing unitdecreases as developing is carried out, it is preferable that the amountof remaining developer is appropriately written to the elements. Here,with the foregoing image forming apparatus, the writing member writesinformation indicating the usage amount of the developer to the elementof a developing unit during the period after that developing unitarrives at the opposing position until it arrives at the detachingposition due to movement of the moving body, and thus even if thedeveloping unit is detached via the attach/detach opening, the usageamount of developer contained in the developing unit can be accuratelyascertained.

It is also possible to achieve an image forming apparatus comprising: amoving body provided with a plurality of attach/detach sections, whereina developing unit is attachable to and detachable from each of theattach/detach sections, and the developing unit has a developercontaining section and an element into which information can be written;a photoconductor on which a latent image can be formed; a writing memberfor writing information into the element; and an attach/detach openingthrough which the developing unit is attached to and detached from theattach/detach section, wherein: in a state in which the developing unitis positioned at an opposing position where the developing unit is inopposition to the photoconductor due to movement of the moving body,development of the latent image with the developer contained in thedeveloping unit is possible; in a state in which the developing unit ispositioned at a detaching position that is different from the opposingposition due to movement of the moving body, detachment of thedeveloping unit from the attach/detach section via the attach/detachopening is possible; during a period from when the developing unitstarts moving from the opposing position until when the developing unitarrives at the detaching position due to movement of the moving body,the writing member writes information into the element of the developingunit; if, during the period from when the developing unit starts movingfrom the opposing position until when the developing unit arrives at thedetaching position, another developing unit adjacent to the developingunit on the upstream side therefrom in a direction of movement of themoving body is to arrive at the opposing position, then the writingmember writes information into the element of the developing unit duringa period until the other developing unit arrives at the opposingposition; the developing unit has a developer bearing body for bearingdeveloper; the image forming apparatus comprises an AC voltage supplysection for supplying an AC voltage; the AC voltage supply sectionsupplies an AC voltage to the developer bearing body; the writing memberwrites information into the element of the developing unit attached tothe attach/detach section when the AC voltage supply section is notsupplying an AC voltage to the developer bearing body; the writingmember writes information into the element in a non-contact state withrespect to the element; a difference between a maximum voltage value anda minimum voltage value of the AC voltage is 1000 volts or more; and thewriting member writes, into the element, information indicating aremaining amount or a usage amount of developer contained in thedeveloping unit provided with the element.

It is also possible to achieve an image forming apparatus comprising: amoving body provided with a plurality of developing unit attach/detachsections, wherein a developing unit having a developer containingsection is attachable to and detachable from each of the developing unitattach/detach sections; a photoconductor unit attach/detach section toand from which a photoconductor unit can be attached and detached,wherein the photoconductor unit has a photoconductor and an element intowhich information can be written; a writing member for writinginformation into the element; and an attach/detach opening through whichthe developing unit is attached to and detached from the attach/detachsection, wherein: in a state in which the developing unit is positionedat an opposing position where the developing unit is in opposition tothe photoconductor due to movement of the moving body, development of alatent image formed on the photoconductor with the developer containedin the developing unit is possible; in a state in which the developingunit is positioned at a detaching position that is different from theopposing position due to movement of the moving body, detachment of thedeveloping unit from the developing unit attach/detach section via theattach/detach opening is possible; and during a period from when thedeveloping unit arrives at the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the writing member writes information into the element ofthe photoconductor unit.

In a configuration in which the developing unit having a developing unitcontaining section can be attached to and detached from the developingunit attach/detach sections, there is a possibility that the developingunit attached to a developing unit attach/detach section may beinadvertently detached via the attach/detach opening. Here, if thephotoconductor unit has an element and information regarding thedeveloping units is written to this element, then there is a possibilitythat the information stored on the element may be incorrect when thedeveloping unit is inadvertently detached via the attach/detach opening.

Here, with the foregoing image forming apparatus, information is writtento the element of the photoconductor unit by the writing member duringthe period after the developing unit arrives at the opposing positionuntil it arrives at the detaching position due to movement of the movingbody, and thus even if the developing unit is inadvertently detached viathe attach/detach opening, the accuracy of the information stored on theelement can be kept from being impaired.

Further, in the image forming apparatus, during a period from when adeveloper bearing body provided in the developing unit that has arrivedat the opposing position ends developing the latent image until when thedeveloping unit arrives at the detaching position, the writing membermay write information into the element of the photoconductor unit.

The amount of developer in a developing unit decreases when the latentimage is developed by the developer bearing body provided in thatdeveloping unit. Here, with the foregoing image forming apparatus,information is written to the element of the photoconductor unit by thewriting member during the period from after developing of the latentimage by the developer bearing body provided in that developing unitthat has arrived at the opposing position has ended until when thatdeveloping unit arrives at the detaching position. Consequently,information about the remaining amount, for example, based on the amountof developer that has been reduced by development is written to theelement of the photoconductor unit.

Further, in the image forming apparatus, during a period from when thedeveloping unit starts moving from the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the writing member may write information into the elementof the photoconductor unit.

With this image forming apparatus, the time from when the developingunit starts moving from the opposing position until it arrives at thedetaching position can be utilized to effectively write information.

Further, in the image forming apparatus, if, during the period from whenthe developing unit starts moving from the opposing position until whenthe developing unit arrives at the detaching position, anotherdeveloping unit adjacent to the developing unit on the upstream sidetherefrom in a direction of movement of the moving body is to arrive atthe opposing position, then the writing member may write informationinto the element of the photoconductor unit during a period until theother developing unit arrives at the opposing position.

With this image forming apparatus, the writing member writes informationto the element of a developing unit during a period until the otherdeveloping unit arrives at the opposing position, and thus even if, forexample, the developing unit is forcibly detached after the otherdeveloping unit has arrived at the opposing position, information willhave already been written to its element.

Further, in the image forming apparatus, the image forming apparatus maycomprise an AC voltage supply section for supplying an AC voltage; andthe writing member may write information into the element of thephotoconductor unit attached to the photoconductor unit attach/detachsection when the AC voltage supply section is not supplying an ACvoltage.

If an AC voltage supply section for supplying AC voltage is provided,then when the AC voltage supply section is supplying AC voltage, thereis a possibility that electromagnetic noise will be generated at itsperiphery.

With the foregoing image forming apparatus, the writing member writesinformation to the element when the AC voltage supply section is notsupplying AC voltage, and thus information can be written accuratelywithout being affected by noise caused by the supply of the AC voltage,for example.

Further, in the image forming apparatus, the developing unit may have adeveloper bearing body for bearing developer; and the AC voltage supplysection may supply an AC voltage to the developer bearing body.

With this image forming apparatus, the writing member writes informationto the element when the AC voltage supply section is not supplying ACvoltage to the developer bearing body, and thus information can bewritten accurately without being affected by noise caused by the supplyof AC voltage to the developer bearing body, for example.

Further, in the image forming apparatus, the image forming apparatus maycomprise a charging member for charging the photoconductor; and the ACvoltage supply section may supply an AC voltage to the charging member.

With this image forming apparatus, the writing member writes informationto the element when the AC voltage supply section is not supplying ACvoltage to the charging member, and thus information can be writtenaccurately without being affected by noise caused by the supply of ACvoltage to the charging member, for example.

Further, in the image forming apparatus, the writing member may writeinformation into the element in a non-contact state with respect to theelement.

With this image forming apparatus, the writing member writes informationto the element in a non-contact state with respect to the element, andthus information can be written to the element without being affected bydefects in the mechanical contact point, for example.

Further, in the image forming apparatus, a difference between a maximumvoltage value and a minimum voltage value of the AC voltage may be 1000volts or more.

When the difference between the maximum voltage value and the minimumvoltage value of the AC voltage is 1000 volts or more, theelectromagnetic noise that is generated also becomes large. With theforegoing image forming apparatus, the writing member writes informationto the element when the AC voltage supply section is not supplying ACvoltage, and thus information can be written accurately without beingaffected by, for example, the large noise caused by the supply of ACvoltage.

Further, in the image forming apparatus, the writing member may write,into the element, information indicating a remaining amount of developercontained in the developing unit.

Since the amount of developer that is contained in a developing unitdecreases as developing is carried out, it is preferable that the amountof remaining developer is appropriately written to the element. Here,with the foregoing image forming apparatus, the writing member writesinformation indicating the remaining amount of the developer to theelement of the photoconductor unit during the period after thedeveloping unit arrives at the opposing position until it arrives at thedetaching position due to movement of the moving body, and thus even ifthe developing unit is detached via the attach/detach opening, theremaining amount of developer contained in the developing unit can beaccurately ascertained.

Further, in the image forming apparatus, the writing member may write,into the element, information indicating a usage amount of developercontained in the developing unit provided with the element.

Since the amount of developer that is contained in a developing unitdecreases as developing is carried out, it is preferable that the amountof remaining developer is appropriately written to the element. Here,with the foregoing image forming apparatus, the writing member writesinformation indicating the usage amount of the developer to the elementof the photoconductor unit during the period after the developing unitarrives at the opposing position until it arrives at the detachingposition due to movement of the moving body, and thus even if thedeveloping unit is detached via the attach/detach opening, the usageamount of developer contained in the developing unit can be accuratelyascertained.

It is also possible to achieve a computer system comprising: a computerunit; and an image forming apparatus that is connected to the computerunit and that includes a moving body provided with a plurality ofattach/detach sections, wherein a developing unit is attachable to anddetachable from each of the attach/detach sections, and the developingunit has a developer containing section and an element into whichinformation can be written; a photoconductor on which a latent image canbe formed; a writing member for writing information into the element;and an attach/detach opening through which the developing unit isattached to and detached from the attach/detach section; wherein, in astate in which the developing unit is positioned at an opposing positionwhere the developing unit is in opposition to the photoconductor due tomovement of the moving body, development of the latent image with thedeveloper contained in the developing unit is possible; and wherein, ina state in which the developing unit is positioned at a detachingposition that is different from the opposing position due to movement ofthe moving body, detachment of the developing unit from theattach/detach section via the attach/detach opening is possible;wherein, during a period from when the developing unit arrives at theopposing position until when the developing unit arrives at thedetaching position due to movement of the moving body, the writingmember writes information into the element of the developing unit.

It is also possible to achieve a computer system comprising: a computerunit; and an image forming apparatus that is connected to the computerunit and that includes a moving body provided with a plurality ofdeveloping unit attach/detach sections, wherein a developing unit havinga developer containing section is attachable to and detachable from eachof the developing unit attach/detach sections; a photoconductor unitattach/detach section to and from which a photoconductor unit can beattached and detached, wherein the photoconductor unit has aphotoconductor and an element into which information can be written; awriting member for writing information into the element; and anattach/detach opening through which the developing unit is attached toand detached from the attach/detach section; wherein, in a state inwhich the developing unit is positioned at an opposing position wherethe developing unit is in opposition to the photoconductor due tomovement of the moving body, development of a latent image formed on thephotoconductor with the developer contained in the developing unit ispossible; and wherein, in a state in which the developing unit ispositioned at a detaching position that is different from the opposingposition due to movement of the moving body, detachment of thedeveloping unit from the developing unit attach/detach section via theattach/detach opening is possible; wherein, during a period from whenthe developing unit arrives at the opposing position until when thedeveloping unit arrives at the detaching position due to movement of themoving body, the writing member writes information into the element ofthe photoconductor unit.

===Overview of Image Forming Apparatus (Laser Beam Printer)===

Next, using FIG. 1 and FIG. 2, an overview of a laser beam printer(hereinafter, also referred to as “printer”) 10, taken as an example ofthe image forming apparatus, is described. FIG. 1 is a diagram fordescribing a configuration in which a developing unit 54 (51, 52, 53)and a photoconductor unit 75 are attached to and detached from a printerunit 10 a. FIG. 2 is a diagram showing main structural components thatconfigure the printer 10. It should be noted that FIG. 2 is a diagram ofa cross section taken perpendicular to the X direction in FIG. 1.Further, the up/down direction is shown by an arrow in FIG. 1 and FIG.2, and for example, a paper supply tray 92 is arranged at a lowersection of the printer 10 and a fusing unit 90 is arranged at an uppersection of the printer 10.

<Attach/Detach Configuration>

The developing unit 54 (51, 52, 53) and the photoconductor unit 75 canbe attached to and detached from the printer unit 10 a. The printer 10is structured by attaching the developing unit 54 (51, 52, 53) and thephotoconductor unit 75 to the printer unit 10 a.

The printer unit 10 a has a first open/close cover 10 b that can beopened and closed, a second open/close cover 10 c that can be opened andclosed and that is provided more to the inside than the first open/closecover 10 b, a photoconductor unit attach/detach opening 10 d throughwhich the photoconductor unit 75 is attached and detached, and adeveloping unit attach/detach opening 10 e through which the developingunit 54 (51, 52, 53) is attached and detached.

Here, when the user opens the first open/close cover 10 b, thephotoconductor unit 75 can be attached to and detached from the printerunit 10 a via the photoconductor unit attach/detach opening 10 d.Further, when the user opens the second open/close cover 10 c, thedeveloping unit 54 (51, 52, 53) can be attached to and detached from theprinter unit 10 a via the developing unit attach/detach opening 10 e.

<Overview of the Printer 10>

An overview of the printer 10 in a state in which the developing unit 54(51, 52, 53) and the photoconductor unit 75 have been attached to theprinter unit 10 a is described.

As shown in FIG. 2, the printer 10 according to the present embodimenthas a charging unit 30, an exposing unit 40, a YMCK developing device50, a first transferring unit 60, an intermediate transferring body 70,and a cleaning blade 76, in the direction of rotation of aphotoconductor 20, which is a latent image bearing body for bearing alatent image. It further includes a second transferring unit 80, afusing unit 90, a display unit 95 made of a liquid crystal panel etc.for constituting a means for making a notification to the user, and acontrol unit 100 (FIG. 3) for controlling these units etc. so as tocontrol the operation of the printer 10.

The photoconductor 20 has a cylindrical conductive base and aphotoconductive layer formed on the outer circumference surface of thisbase, and can rotate about a central shaft. In this embodiment, thephotoconductor rotates in the clockwise direction as shown by an arrowin FIG. 2.

The charging unit 30 is a device for charging the photoconductor 20, andthe exposing unit 40 is a device for forming a latent image on thecharged photoconductor 20 by irradiating laser. The exposing unit 40has, for example, a semiconductor laser, a polygon mirror, and an F-θlens, and irradiates modulated laser onto the charged photoconductor 20based on an image signal that is input from a not-shown host computer,such as a personal computer or a word processor.

The YMCK developing device 50 has a rotary 55, which serves as a movingbody, and four developing units attached to the rotary 55. The rotary 55is capable of rotating, and is provided with four attach/detach sections55 b, 55 c, 55 d, and 55 e to and from which the four developing units51, 52, 53, and 54 can respectively be attached and detached via thedeveloping unit attach/detach opening 10 d. The cyan developing unit 51,which contains cyan (C) toner, can be attached to and detached from theattach/detach section 55 b, the magenta developing unit 52, whichcontains magenta (M) toner, can be attached to and detached from theattach/detach section 55 c, the black developing unit 53, which containsblack (K) toner, can be attached to and detached from the attach/detachsection 55 d, and the yellow developing unit 54, which contains yellow(Y) toner, can be attached to and detached from the attach/detachsection 55 e.

By rotating, the rotary 55 moves the above-mentioned four developingunits 51, 52, 53, and 54 that have been attached to the attach/detachsections 55 b, 55 c, 55 d, and 55 e, respectively. That is, the rotary55 rotates the four attached developing units 51, 52, 53, and 54 about acentral shaft 55 a while maintaining their relative positions. Then, thedeveloping units 51, 52, 53, and 54 are selectively brought intoopposition with the latent image formed on the photoconductor 20 so asto develop the latent image on the photoconductor 20 using the tonercontained in each of the developing units 51, 52, 53, and 54. It shouldbe noted that the developing units are described in detail later.

The first transferring unit 60 is a device for transferring asingle-color toner image formed on the photoconductor 20 onto theintermediate transferring body 70. When the four colors of toner aresuccessively transferred over one another, a full-color toner image isformed on the intermediate transferring body 70.

The intermediate transferring body 70 is an endless belt and isrotatively driven at substantially the same circumferential velocity asthe photoconductor 20. A read sensor for synchronization RS is providednear the intermediate transferring body 70. The read sensor forsynchronization RS is a sensor for detecting the reference position ofthe intermediate transferring body 70, and obtains a synchronizationsignal vsync in the sub-scanning direction, which is perpendicular tothe main scanning direction. The read sensor for synchronization RS hasa light-emitting section for emitting light and a light-receivingsection for receiving light. Light that is emitted from thelight-emitting section passes through a hole formed in a predeterminedposition of the intermediate transferring body 70, and when light isreceived by the light-receiving section, the read sensor forsynchronization RS generates a pulse signal. One pulse signal isgenerated each time the intermediate transferring body 70 makes onerevolution.

The second transferring unit 80 is a device for transferring thesingle-color toner image or the full-color toner image formed on theintermediate transferring body 70 onto a recording medium such as paper,film, or cloth.

The fusing unit 90 is a device for fusing the single-color toner imageor the full-color toner image, which has been transferred onto therecording medium, onto the recording medium, such as paper, to make theimage into a permanent image.

The cleaning blade 76 is made of rubber and abuts against the surface ofthe photoconductor 20. The cleaning blade 76 removes the toner remainingon the photoconductor 20 by scraping it off after the toner image hasbeen transferred onto the intermediate transferring body 70 by the firsttransferring unit 60.

The photoconductor unit 75 is provided between the first transferringunit 60 and the exposing unit 40, and has the photoconductor 20, anelement 75 a to which information can be written, the charging unit 30,the cleaning blade 76, and a waste toner containing section 76 a forcontaining toner that has been scraped off by the cleaning blade 76. Itshould be noted that the element 75 a has a configuration that allowsstorage of various types of information that have been written in.

The control unit 100 is made of a main controller 101 and a unitcontroller 102, as shown in FIG. 3. An image signal is input to the maincontroller 101, and in accordance with a command based on this imagesignal, the unit controller 102 controls each of the above-mentionedunits etc. to form an image.

===Operation of Printer 10===

Next, the operation of the printer 10 configured as above is describedwith reference to other structural components thereof.

First, when an image signal from a not-shown host computer is input tothe main controller 101 of the printer 10 via an interface (I/F) 112,the photoconductor 20 and the intermediate transferring body 70 arerotated due to control by the unit controller 102 based on a commandfrom the main controller 101. Then, the reference position of theintermediate transferring body 70 is detected by the read sensor forsynchronization RS, and a pulse signal is output. This pulse signal issent to the unit controller 102 via a serial interface 121. The unitcontroller 102 controls the following operation, taking the pulsesignal, which has been received, as a reference.

While rotating, the photoconductor 20 is successively charged by thecharging unit 30 at a charging position. The area of the photoconductor20 that has been charged is brought to an exposing position through therotation of the photoconductor 20, and a latent image corresponding toimage information for a first color, for example, yellow Y, is formed inthat area by the exposing unit 40.

The latent image formed on the photoconductor 20 is brought to adeveloping position through the rotation of the photoconductor 20, andis developed with yellow toner by the yellow developing unit 54. Ayellow toner image is thus formed on the photoconductor 20.

The yellow toner image that has been formed on the photoconductor 20 isbrought to a first transferring position through the rotation of thephotoconductor 20 and is transferred onto the intermediate transferringbody 70 by the first transferring unit 60. At this time, a firsttransferring voltage that has a polarity that is opposite from thetoner-charge polarity is applied to the first transferring unit 60. Itshould be noted that throughout this operation the second transferringunit 80 is separated from the intermediate transferring body 70.

The above process is repeated for the second color, the third color, andthe fourth color, and therefore, toner images of each colorcorresponding to each of the image signals are transferred onto theintermediate transferring body 70 in a superposed manner. Thus, afull-color toner image is formed on the intermediate transferring body70.

The full-color toner image that has been formed on the intermediatetransferring body 70 is brought to a second transferring positionthrough the rotation of the intermediate transferring body 70 and istransferred onto a recording medium by the second transferring unit 80.It should be noted that the recording medium is carried from the papersupply tray 92 to the second transferring unit 80 via a paper supplyroller 94 and a resist roller 96. Further, when performing thetransferring operation, the second transferring unit 80 is pressedagainst the intermediate transferring body 70 and supplied with a secondtransferring voltage.

The fusing unit 90 heats and applies pressure to the full-color tonerimage that has been transferred to the recording medium, and the imageis fused to the recording medium.

On the other hand, after the photoconductor 20 passes the firsttransferring position, the toner adhering to its surface is scraped offby the cleaning blade 76 and it is prepared for charging for forming thenext latent image. The toner that has been scraped off is collected inthe waste toner containing section 76 a.

===Overview of Control Unit===

Next, the configuration of the control unit 100 is described withreference to FIG. 3. FIG. 3 is a block diagram showing the control unit100 provided in the printer 10.

The main controller 101 of the control unit 100 is connected to a hostcomputer via the interface 112, and is provided with an image memory 113for storing image signals that are received from the host computer.

The unit controller 102 of the control unit 100 is electricallyconnected to each of the units (the charging unit 30, the exposing unit40, the first transferring unit 60, the photoconductor unit 75, thesecond transferring unit 80, the fusing unit 90, and the display unit95) and the YMCK developing device 50, and by receiving signals from thesensors provided in these components, the unit controller controls eachof these units and the YMCK developing device 50 based on signals inputfrom the main controller 101 as it detects the state of each of theseunits and the YMCK developing device 50. As the structural componentsfor driving each of these units and the YMCK developing device 50, FIG.3 shows a photoconductor unit drive control circuit, a charging unitdrive control circuit, an exposing unit drive control circuit 127, aYMCK developing device drive control circuit 125, a first transferringunit drive control circuit, a second transferring unit drive controlcircuit, a fusing unit drive control circuit, and a display unit drivecontrol circuit.

The exposing unit drive control circuit 127 connected to the exposingunit 40 has a pixel counter 127 a that serves as consumption amountdetection means for detecting the amount of consumption of developer.The pixel counter 127 a counts the number of pixels that are input tothe exposing unit 40. It should be noted that it is also possible toprovide the pixel counter 127 a in the exposing unit 40 or in the maincontroller 101. It should be noted that the number of pixels is thenumber of pixels in units of basic resolution of the printer 10, or inother words, the number of pixels of the image that is actually printed.The amount of consumption of toner T (the usage amount) is proportionalto the number of pixels, and therefore, by counting the number ofpixels, it is possible to detect the amount of consumption of toner T.

To the YMCK developing device drive control circuit 125, an AC voltageis supplied from an AC voltage supply section 126 a and a DC voltage issupplied from a DC voltage supply section 126 b. The YMCK developingdevice drive control circuit 125 applies a voltage, which is obtained bysuperimposing the AC voltage and the DC voltage, to a developing rollerat a suitable timing to form an alternating electric field between thedeveloping roller and the photoconductor.

Further, the CPU 120 provided in the unit controller 102 is connected toa nonvolatile storage element (hereinafter, also referred to as“printer-side memory”) 122 such as a serial EEPROM via the serialinterface (I/F) 121.

Further, the CPU 120 is capable of wirelessly communicating withelements 51 a, 52 a, 53 a, and 54 a, which are respectively providedin/on the developing units 51, 52, 53, and 54, via the serial interface121, a send/receive circuit 123, and a printer-side antenna (antenna forcommunicating with the developing unit elements) 124 b. The CPU 120 isalso capable of wirelessly communicating with the element 75 a of thephotoconductor unit 75 via the serial interface 121, the send/receivecircuit 123, and a printer-side antenna (antenna for communicating withthe photoconductor unit element) 124 a. At the time of wirelesscommunication, the antenna 124 b for communicating with the developingunit elements, which serves as a writing member, writes information intothe elements 51 a, 52 a, 53 a, and 54 a of the developing units 51, 52,53, and 54, respectively. The antenna 124 b for communicating with thedeveloping unit elements, which serves as a writing member, is alsocapable of reading information from the elements 51 a, 52 a, 53 a, and54 a of the developing units 51, 52, 53, and 54, respectively. At thetime of wireless communication, the antenna 124 a for communicating withthe photoconductor unit element, which serves as a writing member,writes information into the element 75 a of the photoconductor unit 75.The antenna 124 a for communicating with the photoconductor unitelement, which serves as a write means, can also read information fromthe element 75 a of the photoconductor unit 75.

===Overview of Developing Units===

Next, an overview of the developing units is described using FIG. 4 andFIG. 5. FIG. 4 is a perspective view of the yellow developing unit 54seen from the side of a developing roller 510. FIG. 5 is across-sectional view showing main structural components of the yellowdeveloping unit 54. It should be noted that in FIG. 5 as well, theup/down direction is shown by an arrow, and for example, the centralaxis of the developing roller 510 is located lower than the central axisof the photoconductor 20. Further, in FIG. 5, the yellow developing unit54 is shown in a state in which it is positioned at a developingposition that is in opposition to the photoconductor 20.

The YMCK developing device 50 is provided with the cyan developing unit51, which contains cyan (C) toner, the magenta developing unit 52, whichcontains magenta (M) toner, the black developing unit 53, which containsblack (K) toner, and the yellow developing unit 54, which containsyellow (Y) toner. Since the configuration of each of these developingunits is the same, the yellow developing unit 54 is described below.

The yellow developing unit 54 is provided with, for example, a developercontaining section, that is, a first containing section 530 and a secondcontaining section 535 for containing yellow toner T which serves as thedeveloper, the element 54 a, a housing 540, the developing roller 510which serves as the developer bearing roller, a toner supply roller 550for supplying toner T to the developing roller 510, and a restrictionblade 560 for restricting the thickness of the layer of toner T that isbore on the developing roller 510.

The housing 540 is manufactured by joining, for example, an upperhousing and a lower housing which have been integrally molded, and theinside of the housing is divided into the first containing section 530and the second containing section 535 by a restriction wall 545 thatextends upward from the lower section (in the up/down direction of FIG.5). The first containing section 530 and the second containing section535 form developer containing sections (530, 535) for containing toner Twhich serves as a developer. The upper sections of the first containingsection 530 and the second containing section 535 are in communication,and the movement of the toner T between them is restricted by therestriction wall 545. It should be noted that it is also possible toprovide a stirring member for stirring the toner T contained in thefirst containing section 530 and the second containing section 535. Inthe present embodiment, however, each of the developing units (the cyandeveloping unit 51, the magenta developing unit 52, the black developingunit 53, and the yellow developing unit 54) rotates in conjunction withthe rotation of the rotary 55 so that the toner T in each developingunit is stirred. Therefore, a stirring member is not provided in thefirst containing section 530 or the second containing section 535.

The element 54 a, into which information can be written, is provided onthe outer surface of the housing 540. The element 54 a has aconfiguration that allows written information to be stored. Toeffectively write information into the element 54 a, the longitudinaldirection of the element 54 a intersects with the longitudinal directionof the yellow developing unit 54. More preferably, it is also possibleto achieve a configuration in which the longitudinal direction of theelement 54 a is perpendicular to the longitudinal direction of theyellow developing unit 54. The element 54 a will be described in greaterdetail later, but here it should be noted that the element 54 a isprovided with an antenna 54 d, and that the longitudinal direction ofthe antenna 54 a also intersects with the longitudinal direction of theyellow developing unit 54.

An opening 541 that communicates with the outside of the housing 540 isprovided in the lower section of the first containing section 530. Thetoner supply roller 550 is provided in the first containing section 530with its circumferential surface facing the opening 541, and isrotatably supported on the housing 540. Further, the developing roller510 is provided with its circumferential surface facing the opening 541from outside the housing 540, and the developing roller 510 abutsagainst the toner supply roller 550.

The developing roller 510 bears toner T and carries the toner to adeveloping position, which is in opposition to the photoconductor 20.The developing roller 510 is made of, for example, aluminum, stainlesssteel, or iron, and if necessary, it can be subjected to nickel platingor chromium plating, and the toner bearing region can be subjected tosandblasting or the like. Further, the developing roller 510 can rotateabout its central axis, and as shown in FIG. 5, it rotates in theopposite direction (in FIG. 5, the counterclockwise direction) to therotating direction of the photoconductor 20 (in FIG. 5, the clockwisedirection). Its central axis is located lower than the central axis ofthe photoconductor 20. Further, as shown in FIG. 5, in a state in whichthe yellow developing unit 54 is in opposition to the photoconductor 20,a gap exists between the developing roller 510 and the photoconductor20. That is, the yellow developing unit 54 develops the latent imageformed on the photoconductor 20 in a non-contacting state. It should benoted that when the latent image formed on the photoconductor 20 isdeveloped, an alternating electric field is generated between thedeveloping roller 510 and the photoconductor 20.

The toner supply roller 550 supplies, to the developing roller 510, thetoner T contained in the first containing section 530 and the secondcontaining section 535. The toner supply roller 550 is made ofpolyurethane foam, for example, and abuts against the developing roller510 in a state in which it is elastically deformed. The toner supplyroller 550 is arranged at a lower section of the first containingsection 530, and the toner T contained in the first containing section530 and the second containing section is supplied to the developingroller 510 by the toner supply roller 550 at the lower section of thefirst containing section 530. The toner supply roller 550 can rotateabout its central axis, and its central axis is located lower than thecentral rotation axis of the developing roller 510. Further, the tonersupply roller 550 rotates in the opposite direction (in FIG. 5, theclockwise direction) to the rotating direction of the developing roller510 (in FIG. 5, the counterclockwise direction). It should be noted thatthe toner supply roller 550 has the function of supplying the toner Tthat is contained in the first containing section 530 and the secondcontaining section 535 to the developing roller 510 as well as thefunction of stripping off, from the developing roller 510, the toner Tthat remains on the developing roller 510 after development.

The restriction blade 560 restricts the thickness of the toner T layerborne by the developing roller 510, and gives charge to the toner Tborne by the developing roller 510. The restriction blade 560 has arubber section 560 a and a rubber support section 560 b. The rubbersection 560 a is made of, for example, silicone rubber or urethanerubber, and the rubber support section 560 b is a thin plate made of,for example, phosphor bronze or stainless steel, and has a springycharacteristic. The rubber section 560 a is supported by the rubbersupport section 560 b, and one end of the rubber support section 560 bis fixed to a blade support metal plate 562. The blade support metalplate 562 is fastened to a seal frame 526, which is described later, andis attached to the housing 540 together with the restriction blade 560,forming a part of a seal unit 520, which is described later. In thisstate, the rubber section 560 a is pressed against the developing roller510 by the elastic force created by the flexure of the rubber supportsection 560 b.

Further, a blade backing member 570 made of Moltoprene or the like isprovided on one side of the restriction blade 560 opposite from the sideof developing roller 510. The blade backing member 570 prevents thetoner T from entering in between the rubber support section 560 b andthe housing 540 to stabilize the elastic force caused by the flexure ofthe rubber support section 560 b, and also presses the rubber section560 a against the developing roller 510 by applying force to the rubbersection 560 a toward the developing roller 510 from directly behind therubber section 560 a. Consequently, the blade backing member 570improves the contact uniformity and the sealing properties of the rubbersection 560 a with respect to the developing roller 510.

The end of the restriction blade 560 on the side opposite from the sidesupported by the blade support metal plate 562, that is, its tip, is notin contact with the developing roller 510; rather, a section at apredetermined distance from its tip contacts, with some breadth, thedeveloping roller 510. That is, the restriction blade 560 does not abutagainst the developing roller 510 at its edge but rather at its midsection. Further, the restriction blade 560 is arranged such that itstip is facing upstream in the rotating direction of the developingroller 510, and thus, makes a so-called counter-abutment with respect tothe roller. It should be noted that the abutting position where therestriction blade 560 abuts against the developing roller 510 is locatedlower than the central axis of the developing roller 510 and is alsolocated lower than the central axis of the toner supply roller 550.

The seal member 520 prevents the toner T in the yellow developing unit54 from spilling out from the unit, and also collects the toner T on thedeveloping roller 510, which has passed the developing position, intothe developing unit without scraping it off. The seal member 520 is aseal made of polyethylene film or the like. The seal member 520 issupported by a seal support metal plate 522, and is attached to theframe 540 via the seal support metal plate 522. A seal urging member 524made of Moltoprene or the like is provided on one side of the sealmember 520 opposite from the side of the developing roller 510, and dueto the elastic force of the seal urging member 524, the seal member 520is pressed against the developing roller 510. It should be noted thatthe abutting position where the seal member 520 abuts against thedeveloping roller 510 is located above the central axis of thedeveloping roller 510.

In the yellow developing unit 54 configured in this manner, the tonersupply roller 550 supplies, to the developing roller 510, the toner Tthat is contained in the first containing section 530 and the secondcontaining section 535, which serve as developer containing sections.The toner T that is supplied to the developing roller 510 is brought tothe abutting position of the restriction blade 560 in conjunction withthe rotation of the developing roller 510, and when it passes theabutting position, the thickness of the toner layer is restricted andthe toner is charged. Then, due to further rotation of the developingroller 510, the toner T on the developing roller 510, whose layerthickness has been restricted, is brought to the developing positionopposing the photoconductor 20, and is used for developing the latentimage formed on the photoconductor 20 under the alternating electricfield at the developing position. The toner T on the developing roller510 that has passed the developing position due to further rotation ofthe developing roller 510 passes the seal member 520 and is collectedinto the developing unit by the seal member 520 without being scrapedoff.

===Configuration of Elements===

Next, the configuration of the elements of the developing units and theelement of the photoconductor unit, including the configuration forsending and receiving data, is described with reference to FIG. 6A, FIG.6B, FIG. 7, and FIG. 8. FIG. 6A is a plan perspective view showing theconfiguration of an element. FIG. 6B is a block diagram for describingthe internal configuration of the element and the send/receive section.FIG. 7 is a diagram for describing the information stored in a memorycell 54 h of the element 54 a. FIG. 8 is a diagram for describing theinformation stored in the memory cell of the element 54 a of thephotoconductor unit 75.

Since the elements of the developing units other than the yellowdeveloping unit 54 also have the same configuration, the element 54 a ofthe yellow developing unit 54 is taken as an example and describedbelow.

If the element 54 a and the printer-side antenna 124 b are in apredetermined positional relationship, for example, if they are within10 mm of one another, information can be sent and received without theelement and the antenna being in contact with one another. The element54 a is overall very compact and thin, and one of its sides can be madeadhesive and can be made to adhere to an object as a sticker. It isknown as a memory tag, for example, and is sold commercially in variousforms.

The element 54 a has a non-contact IC chip 54 b, a resonant capacitor 54c that is formed by etching a metal film, and a flat coil serving as anantenna 54 d. These are mounted onto a plastic film and covered by atransparent coversheet.

The printer unit 10 a has a coil that serves as the printer-side antenna124 b, the send/receive circuit 123, and the serial interface 121 thatis connected to the controller (CPU) 120 of the printer unit 10 a.

The non-contact IC chip 54 b has a rectifier 54 e, a signal analysissection RF (Radio Frequency) 54 f, a controller 54 g, and the memorycell 54 h. The memory cell 54 h is a nonvolatile memory that can beelectrically read and written, such as an NAND flash ROM, and is capableof storing information that has been written and allows the storedinformation to be read from the outside.

The antenna 54 d of the element 54 a and the printer-side antenna 124 bwirelessly communicate with one another to read information stored inthe memory cell 54 h and write information into the memory cell 54 h.Further, the high frequency signals that are generated by thesend/receive circuit 123 of the printer unit 10 a are induced as a highfrequency magnetic field via the printer-side antenna 124 b. This highfrequency magnetic field is absorbed via the antenna 54 d of the element54 a, is rectified by the rectifier 54 e, and becomes a DC power sourcefor driving each of the circuits in the IC chip 54 b.

The memory cell 54 h of the element 54 a stores various types ofinformation, as shown in FIG. 7. The address 00H stores unique IDinformation for each element, such as the serial number of the element.The address 01H stores the date that the developing unit wasmanufactured. The address 02H stores information for specifying thedestination of the developing unit. The address 03H stores informationfor specifying the manufacturing line on which the developing unit wasmanufactured. The address 04H stores information for specifying modelswith which the developing unit is compatible. The address 05H storestoner remaining amount information as information indicating the amountof toner that is contained in the developing unit. The address 06H andsubsequent areas store appropriate information.

The ID information that is stored on the memory cell 54 h of the element54 a can be written at the time that the storage element is manufacturedin the factory. The main unit of the printer 10 can read this IDinformation to identify each of the elements 54 a, 51 a, 52 a, and 53 a.

It should be noted that the element 75 a of the photoconductor unit 75has the same configuration. The memory cell of the element of thephotoconductor unit 75 stores various types of information, as shown inFIG. 8.

The address 00H stores unique ID information for each element, such asthe serial number of the element. The address 01H stores the date thatthe photoconductor unit was manufactured. The address 02H storesinformation for specifying the destination of the photoconductor unit.The address 03H stores information for specifying the manufacturing lineon which the photoconductor unit was manufactured. The address 04Hstores information for specifying models with which the photoconductorunit is compatible. The address 05H stores information indicating thetotal number of printed sheets of the printer unit 10 a when thephotoconductor unit is attached to the printer unit 10 a. The address06H stores information indicating the total number of printed sheets ofthe printer unit 10 a when the photoconductor unit has reached itsservice life and is detached from the printer unit 10 a. The address 07Hstores the number of sheets for which color printing has been performedusing the photoconductor unit. The address 08H stores the number ofsheets for which monochrome printing has been performed using thephotoconductor unit. The address 09H stores the number of sheetsdeveloped by the yellow developing unit 54, that is, the number ofsheets printed using yellow toner. The address 0AH stores the number ofsheets developed by the magenta developing unit 52, that is, the numberof sheets printed using magenta toner. The address 0BH stores the numberof sheets developed by the cyan developing unit 51, that is, the numberof sheets printed using cyan toner. The address 0CH stores the number ofsheets developed by the black developing unit 53, that is, the number ofsheets printed using black toner. The address 0DH and subsequent areasstore appropriate information.

===Relationship Between Element and Printer-side Antenna===

Next, the relationship between the elements of the developing units andthe printer-side antenna 124 b is described with reference to FIG. 9Athrough C. FIG. 9A is a diagram for describing the relationship betweenthe element and the printer-side antenna when the yellow developing unit54 is positioned at the developing position. FIG. 9B is a diagram fordescribing the relationship between the element and the printer-sideantenna when the yellow developing unit 54 is positioned at theattach/detach position. FIG. 9C is a diagram for describing therelationship between the element and the printer-side antenna when therotary 55 is positioned at the home position.

In FIG. 9A, the yellow developing unit 54 is positioned at thedeveloping position (opposing position), and the element 54 a of theyellow developing unit 54 is in opposition to the printer-side antenna124 b in a non-contact state.

The printer-side antenna 124 b is provided so that its longitudinaldirection (in FIG. 9A, the Y direction) is in the direction of rotationof the rotary 55 (in FIG. 9A, the Z direction). By arranging theprinter-side antenna 124 b in this manner, wireless communication can becarried out effectively between the printer-side antenna 124 b and theelement 54 a. That is, the printer-side antenna 124 b can wirelesslycommunicate with the element 54 a not only in the state shown in FIG. 9Abut also in a state in which the rotary 55 has been rotated by apredetermined angle. By making the longitudinal direction of theprinter-side antenna 124 b follow the direction of rotation of therotary 55, the range of angle of rotation of the rotary 55 in whichwireless communication is possible can be made large.

Also, the length of the printer-side antenna 124 b in the longitudinaldirection is longer than the length of the element 54 a in thatlongitudinal direction. Thus, it is possible to achieve more effectivewireless communication with respect to the element 54 a of the yellowdeveloping unit 54 that has been attached to the attach/detach section55 e provided in the rotary 55.

Further, the printer-side antenna 124 b is provided more to the outsidethan the element 54 a in the radial direction of rotation of the rotary55. Thus, using the printer-side antenna 124 b, which is provided moreto the outside than the element 54 a in the radial direction of rotationof the rotary 55, effective wireless communication with respect to theelement 54 a of the yellow developing unit 54 can be achieved.

It should be noted that the printer-side antenna 124 b can wirelesslycommunicate with the element 54 a not only when the rotary 55 is in astopped state but also when the rotary 55 is in a moving state. That is,the printer-side antenna 124 b can wirelessly communicate with theelement 54 a even if the element is moving.

Further, the printer-side antenna 124 a is in opposition to the element75 a of the photoconductor unit 75 in a non-contact state (see FIG. 2),and the printer-side antenna 124 a can wirelessly communicate with theelement 75 a of the photoconductor unit 75 in a non-contact state.

===Rotation of Rotary 55 and Attach/Detach Position (Attaching andDetaching Position) of Developing Units===

Next, the relationship between the rotation of the rotary 55 and theposition where the developing units are detached is described withreference again to FIG. 9A to FIG. 9C.

As described above, in the state shown in FIG. 9A, the yellow developingunit 54 is positioned at the developing position. When the rotary 55 isrotated from this state by a predetermined angle in the Z direction, thestate shown in FIG. 9B is attained. In the state shown in FIG. 9B, theyellow developing unit 54 is positioned at the developing position. Inthis state, the yellow developing unit 54 can be attached and detachedvia the attach/detach opening 10 e, that is, it can be mounted to theattach/detach section 55 e or it can be removed from the attach/detachsection 55 e. Then, when the rotary 55 is rotated from the state shownin FIG. 9B by a predetermined angle in the Z direction, the cyandeveloping unit 51, which is positioned upstream in the direction ofrotation of the rotary 55, is positioned at the developing position.

It should be noted that FIG. 9C shows a state in which the rotary 55 ispositioned at the home position after the printer 10 has been turned ONand the initialization operation has been performed.

===Writing Information into Elements of Developing Units===

Next, the writing of information into the elements of the developingunits is described with reference to FIG. 10. FIG. 10 is a flowchart fordescribing how information is written into the elements of thedeveloping units.

<Step of Standby for Image Forming Process (Step 1)>

When the printer 10 is turned ON, a predetermined initializationoperation is performed, and the printer 10 enters an image formingprocess standby state. When an image signal, which is an image formingprocess command from the host computer, is input to the main controller101 of the printer 10 via the interface (I/F) 112, the photoconductor 20and the intermediate transferring body 70 are rotated. Then, the readsensor for synchronization RS detects the reference position of theintermediate transferring body 70 and outputs a pulse signal. The unitcontroller 102 executes the following control, taking the pulse signalthat has been received as a reference.

<Step of Starting Counting Number of Yellow Pixels (Step 3)>

A latent image that corresponds to the yellow image information isformed on the charged photoconductor by the exposing unit 40. At thistime, the pixel counter 127 a starts counting the number of pixels thatare input to the exposing unit 40.

<Step of Moving Yellow Developing Unit (Step 5)>

The rotary 55 is rotated, and the yellow developing unit 54 is moved tothe developing position.

<Step of Starting Application of Yellow Developing Bias (Step 7)>

Application of a developing bias to the developing roller of the yellowdeveloping unit 54 is started. Thus, the latent image formed on thephotoconductor 20 is developed by yellow toner. The developing bias thatis applied is a voltage obtained by superimposing an AC voltage and a DCvoltage, as mentioned above. It should be noted that the developing biasmay be applied to the developing roller before the yellow developingunit 54 arrives at the developing position, or the developing bias maybe applied to the developing roller after the yellow developing unit 54arrives at the developing position.

<Step of Ending Application of Yellow Developing Bias (Step 9)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the yellow developing unit 54 is ended. Thus, theoperation of developing with the yellow developing unit 54 is ended.

<Step of Obtaining Number of Yellow Pixels (Step 11)>

The number of pixels that have been counted is obtained from the pixelcounter 127 a. The number of counted pixels is proportional to theamount of consumption of toner, and thus the amount of consumption ofyellow toner YT can be found.

<Step of Reading and Storing Yellow Toner Remaining Amount (Step 13)>

The remaining amount of yellow toner YY that is stored in the RAM isread out from the RAM, and a value YYnew obtained by subtracting theconsumption amount YT from the remaining amount YY is stored in the RAMas the new remaining amount.

<Step of Starting Movement of Cyan Developing Unit (Step 15)>

The rotary 55 starts rotating so as to position the cyan developing unit51 at the developing position.

<Step of Writing Information into Element 54 a (Step 17)>

The value YYnew obtained by subtracting the consumption amount YT fromthe remaining amount YY is written into the element 54 a of the yellowdeveloping unit 54. This writing is carried out using the printer-sideantenna 124 b, without it being in contact with the element 54 a whichis moving. It should be noted that when this writing is carried out, theyellow developing unit 54 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Starting Counting Number of Cyan Pixels (Step 19)>

A latent image that corresponds to the cyan image information is formedon the charged photoconductor by the exposing unit 40. At this time, thepixel counter 127 a starts counting the number of pixels that are inputto the exposing unit 40.

<Step of Ending Movement of Cyan Developing Unit (Step 21)>

The rotation of the rotary 55 for positioning the cyan developing unit51 at the developing position is ended. Thus, the cyan developing unit51 arrives at the developing position.

<Step of Starting Application of Cyan Developing Bias (Step 23)>

Application of a developing bias to the developing roller of the cyandeveloping unit 51 is started. Thus, the latent image formed on thephotoconductor 20 is developed by cyan toner.

<Step of Ending Application of Cyan Developing Bias (Step 25)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the cyan developing unit 51 is ended. Thus, theoperation of developing with the cyan developing unit 51 is ended.

<Step of Obtaining Number of Cyan Pixels (Step 26)>

The number of pixels that have been counted is obtained from the pixelcounter 127 a. The number of counted pixels is proportional to theamount of consumption of toner, and thus the amount of consumption ofcyan toner CT can be found.

<Step of Reading and Storing Cyan Toner Remaining Amount (Step 27)>

The remaining amount of cyan toner CC that is stored in the RAM is readout from the RAM, and a value CCnew obtained by subtracting theconsumption amount CT from the remaining amount CC is stored in the RAMas the new remaining amount.

<Step of Starting Movement of Magenta Developing Unit (Step 29)>

The rotary 55 starts rotating so as to position the magenta developingunit 52 at the developing position.

<Step of Writing Information into Element 51 a (Step 31)>

The value CCnew obtained by subtracting the consumption amount CT fromthe remaining amount CC is written into the element 51 a of the cyandeveloping unit 51. This writing is carried out using the printer-sideantenna 124 b, without it being in contact with the element 51 a whichis moving. It should be noted that when this writing is carried out, thecyan developing unit 51 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Starting Counting Number of Magenta Pixels (Step 33)>

A latent image that corresponds to the magenta image information isformed on the charged photoconductor by the exposing unit 40. At thistime, the pixel counter 127 a starts counting the number of pixels thatare input to the exposing unit 40.

<Step of Ending Movement of Magenta Developing Unit (Step 35)>

The rotation of the rotary 55 for positioning the magenta developingunit 52 at the developing position is ended. Thus, the magentadeveloping unit 52 arrives at the developing position.

<Step of Starting Application of Magenta Developing Bias (Step 37)>

Application of a developing bias to the developing roller of the magentadeveloping unit 52 is started. Thus, the latent image formed on thephotoconductor 20 is developed by magenta toner.

<Step of Ending Application of Magenta Developing Bias (Step 39)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the magenta developing unit 52 is ended. Thus, theoperation of developing with the magenta developing unit 52 is ended.

<Step of Obtaining Number of Magenta Pixels (Step 41)>

The number of pixels that have been counted is obtained from the pixelcounter 127 a. The number of counted pixels is proportional to theamount of consumption of toner, and thus the amount of consumption ofmagenta toner MT can be found.

<Step of Reading and Storing Magenta Toner Remaining Amount (Step 43)>

The remaining amount of magenta toner MM that is stored in the RAM isread out from the RAM, and a value MMnew obtained by subtracting theconsumption amount MT from the remaining amount MM is stored in the RAMas the new remaining amount.

<Step of Starting Movement of Black Developing Unit (Step 45)>

The rotary 55 starts rotating so as to position the black developingunit 53 at the developing position.

<Step of Writing Information into Element 52 a (Step 47)>

The value MMnew obtained by subtracting the consumption amount MT fromthe remaining amount MM is written into the element 52 a of the magentadeveloping unit 52. This writing is carried out using the printer-sideantenna 124 b, without it being in contact with the element 52 a whichis moving. It should be noted that when this writing is carried out, themagenta developing unit 52 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Starting Counting Number of Black Pixels (Step 49)>

A latent image that corresponds to the black image information is formedon the charged photoconductor by the exposing unit 40. At this time, thepixel counter 127 a starts counting the number of pixels that are inputto the exposing unit 40.

<Step of Ending Movement of Black Developing Unit (Step 51)>

The rotation of the rotary 55 for positioning the black developing unit53 at the developing position is ended. Thus, the black developing unit53 arrives at the developing position.

<Step of Starting Application of Black Developing Bias (Step 53)>

Application of a developing bias to the developing roller of the blackdeveloping unit 53 is started. Thus, the latent image formed on thephotoconductor 20 is developed by black toner.

<Step of Ending Application of Black Developing Bias (Step 55)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the black developing unit 53 is ended. Thus, theoperation of developing with the black developing unit 53 is ended.

<Step of obtaining Number of Black Pixels (Step 57)>

The number of pixels that have been counted is obtained from the pixelcounter 127 a. The number of counted pixels is proportional to theamount of consumption of toner, and thus the amount of consumption ofblack toner BT can be found.

<Step of Reading and Storing Black Toner Remaining Amount (Step 59)>

The remaining amount of black toner BB that is stored in the RAM is readout from the RAM, and a value BBnew obtained by subtracting theconsumption amount BT from the remaining amount BB is stored in the RAMas the new remaining amount.

<Step of Starting Movement to Home Position (Step 61)>

Rotation of the rotary 55 is started so as to position the rotary 55 atthe home position.

<Step of Writing Information into Element 53 a (Step 63)>

The value BBnew obtained by subtracting the consumption amount BT fromthe remaining amount BB is written into the element 53 a of the blackdeveloping unit 53. This writing is carried out using the printer-sideantenna 124 b, without it being in contact with the element 53 a whichis moving. It should be noted that when this writing is carried out, theblack developing unit 53 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Ending Printing Operation (Step 65)>

When the rotary 55 arrives at the home position, the image formingprocess is ended, and the printer enters the image forming processstandby state.

The process described above is only one example, and modifications tothe above may be made freely as long as the printer-side antenna 124 b,which serves as a writing member, can write information into the elementof a developing unit during the period from when that developing unitarrives at the opposing position (developing position) until it arrivesat the detaching position (attach/detach position) due to movement ofthe rotary 55.

In the case of a configuration in which developing units having anelement and a developer containing section can be attached to anddetached from the attach/detach section, there is a possibility that adeveloping unit attached to the attach/detach section may inadvertentlybe detached via the attach/detach opening 10 e. In particular, since theamount of developer in a developing unit decreases when developing iscarried out with that developing unit positioned at the opposingposition, when that developing unit is detached before information aboutthe amount of developer that has decreased is written to its element, itmay not be possible to ascertain the amount of developer contained inthe developing unit, for example.

Here, with the foregoing image forming apparatus, information about theremaining amount of developer, for example, is written into the elementof the developing unit by the writing member during the period from whenthat developing unit arrives at the opposing position until it arrivesat the detaching position due to movement of the rotary 55, and thus,even if the developing unit is detached via the attach/detach opening 10e, the amount of developer contained in the developing unit, forexample, can be accurately ascertained.

In particular, it is preferable that the writing member writesinformation into the element of a developing unit during the period fromafter developing of the latent image by the developer bearing bodyprovided in that developing unit that has arrived at the opposingposition has ended until when that developing unit arrives at thedetaching position.

The amount of developer in a developing unit decreases when the latentimage is developed by the developer bearing body provided in thatdeveloping unit. Here, with the foregoing image forming apparatus,information is written to the element of the developing unit by thewriting member during the period from after developing of the latentimage by the developer bearing body provided in that developing unitthat has arrived at the opposing position has ended until when thatdeveloping unit arrives at the detaching position. Consequently,information about the remaining amount, for example, based on the amountof developer that has been reduced by development is written to theelement of the developing unit.

It is also preferable that the writing member writes information to theelement of a developing unit during a period from when the developingunit starts moving from the opposing position until when the developingunit arrives at the detaching position due to movement of the rotary 55.

With this image forming apparatus, the time from when the developingunit starts moving from the opposing position until it arrives at thedetaching position can be utilized to effectively write information.

Also, in the example described above, after the yellow developing unit54 began moving from the developing position, first, the yellowdeveloping unit 54 arrived at the attach/detach position where it can beattached and detached, and then when the rotary 55 rotated further, thecyan developing unit 51 upstream in the direction of rotation arrived atthe developing position. However, it is also possible that after theyellow developing unit 54 has begun moving from the developing position,the cyan developing unit 51 upstream in the direction of rotation firstarrives at the developing position, and then when the rotary 55 rotatesfurther, the yellow developing unit 54 arrives at the attach/detachposition where it can be attached and detached.

In this way, if, during the time that a developing unit starts movingfrom the developing position until it arrives at the attach/detachposition, another developing unit adjacent to said developing unit onthe upstream side in the rotating direction of the rotary arrives at thedeveloping position, then it is preferable that the printer-side antenna124 b writes information to the element of the developing unit during aperiod until the other developing unit arrives at the developingposition. The printer-side antenna 124 b writes information to theelement of said developing unit during a period until the otherdeveloping unit arrives at the developing position, and thus even if,for example, the developing unit is forcibly detached after the otherdeveloping unit arrives at the developing position, information willhave already been written to the element of said developing unit.

As described above, it is preferable that the printer-side antenna 124 bwrites information to an element when the AC voltage supply section 126a is not supplying AC voltage to the developing roller 510. By writinginformation at this timing, information can be written accuratelywithout being affected by the noise caused by supplying AC voltage tothe developing roller 510, for example.

===Writing Information into Element of Photoconductor Unit===

Next, the writing of information into the element 75 a of thephotoconductor unit 75 is described with reference to FIG. 11. FIG. 11is a flowchart showing an example in which information is written intothe element 75 a of the photoconductor unit 75. More specifically, anexample is shown in which the number of sheets printed by eachdeveloping unit, that is, the number of sheets printed by each tonercolor, is written into the element 75 a.

<Step of Standby for Image Forming Process (Step 101)>

When the printer 10 is turned ON, a predetermined initializationoperation is performed, and the printer 10 enters an image formingprocess standby state. When an image signal, which is an image formingprocess command from the host computer, is input to the main controller101 of the printer 10 via the interface (I/F) 112, the photoconductor 20and the intermediate transferring body 70 are rotated. Then, the readsensor for synchronization RS detects the reference position of theintermediate transferring body 70 and outputs a pulse signal. The unitcontroller 102 executes the following control, taking the pulse signalthat has been received as a reference.

<Step of Moving Yellow Developing Unit (Step 105)>

The rotary 55 moves so as to position the yellow developing unit 54 atthe developing position.

<Step of Starting Application of Yellow Developing Bias (Step 107)>

Application of a developing bias to the developing roller of the yellowdeveloping unit 54 is started. Thus, the latent image formed on thephotoconductor 20 is developed by yellow toner. The developing bias thatis applied is a voltage obtained by superimposing an AC voltage and a DCvoltage, as mentioned above. It should be noted that the developing biasmay be applied to the developing roller before the yellow developingunit 54 arrives at the developing position, or the developing bias maybe applied to the developing roller after the yellow developing unit 54arrives at the developing position.

<Step of Ending Application of Yellow Developing Bias (Step 109)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the yellow developing unit 54 is ended. Thus, theoperation of developing with the yellow developing unit 54 is ended.

<Step of Starting Movement of Cyan Developing Unit (Step 115)>

The rotary 55 starts rotating so as to position the cyan developing unit51 at the developing position.

<Step of Writing Information into Element 75 a (Step 117)>

Information indicating that the number of sheets printed by the yellowdeveloping unit 54 has increased by one sheet is written into theelement 75 a of the photoconductor unit 75 as the “Number of SheetsPrinted in Yellow” (see FIG. 8). This writing is carried out using theprinter-side antenna 124 a, without it being in contact with the element75 a. It should be noted that when this writing is carried out, theyellow developing unit 54 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e. Also, as the method for writing information indicatingthat the number of sheets printed by the yellow developing unit 54 hasincreased by one sheet, it is possible to adopt, for example, a methodof storing data indicating the total number of sheets printed by theyellow developing unit 54 in a RAM provided in the printer unit 10 a andthen writing, into the element 75 a of the photoconductor unit 75, avalue obtained by adding 1 to the above-mentioned data.

<Step of Ending Movement of Cyan Developing Unit (Step 121)>

The rotation of the rotary 55 for positioning the cyan developing unit51 at the developing position is ended. Thus, the cyan developing unit51 arrives at the developing position.

<Step of Starting Application of Cyan Developing Bias (Step 123)>

Application of a developing bias to the developing roller of the cyandeveloping unit 51 is started. Thus, the latent image formed on thephotoconductor 20 is developed by cyan toner.

<Step of Ending Application of Cyan Developing Bias (Step 125)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the cyan developing unit 51 is ended. Thus, theoperation of developing with the cyan developing unit 51 is ended.

<Step of Starting Movement of Magenta Developing Unit (Step 129)>

The rotary 55 starts rotating so as to position the magenta developingunit 52 at the developing position.

<Step of Writing Information into Element 75 a (Step 131)>

Information indicating that the number of sheets printed by the cyandeveloping unit 51 has increased by one sheet is written into theelement 75 a of the photoconductor unit 75 as the “Number of SheetsPrinted in Cyan” (see FIG. 8). This writing is carried out using theprinter-side antenna 124 a, without it being in contact with the element75 a. It should be noted that when this writing is carried out, the cyandeveloping unit 51 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Ending Movement of Magenta Developing Unit (Step 135)>

The rotation of the rotary 55 for positioning the magenta developingunit 52 at the developing position is ended. Thus, the magentadeveloping unit 52 arrives at the developing position.

<Step of Starting Application of Magenta Developing Bias (Step 137)>

Application of a developing bias to the developing roller of the magentadeveloping unit 52 is started. Thus, the latent image formed on thephotoconductor 20 is developed by magenta toner.

<Step of Ending Application of Magenta Developing Bias (Step 139)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the magenta developing unit 52 is ended. Thus, theoperation of developing with the magenta developing unit 52 is ended.

<Step of Starting Movement of Black Developing Unit (Step 145)>

The rotary 55 starts rotating so as to position the black developingunit 53 at the developing position.

<Step of Writing Information into Element 75 a (Step 147)>

Information indicating that the number of sheets printed by the magentadeveloping unit 52 has increased by one sheet is written into theelement 75 a of the photoconductor unit 75 as the “Number of SheetsPrinted in Magenta” (see FIG. 8). This writing is carried out using theprinter-side antenna 124 a, without it being in contact with the element75 a. It should be noted that when this writing is carried out, themagenta developing unit 52 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Ending Movement of Black Developing Unit (Step 151)>

The rotation of the rotary 55 for positioning the black developing unit53 at the developing position is ended. Thus, the black developing unit53 arrives at the developing position.

<Step of Starting Application of Black Developing Bias (Step 153)>

Application of a developing bias to the developing roller of the blackdeveloping unit 53 is started. Thus, the latent image formed on thephotoconductor 20 is developed by black toner.

<Step of Ending Application of Black Developing Bias (Step 155)>

At a predetermined timing, application of the developing bias to thedeveloping roller of the black developing unit 53 is ended. Thus, theoperation of developing with the black developing unit 53 is ended.

<Step of Writing Information into Element 75 a (Step 161)>

Information indicating that the number of sheets printed by the blackdeveloping unit 53 has increased by one sheet is written into theelement 75 a of the photoconductor unit 75 as the “Number of SheetsPrinted in Black” (see FIG. 8). This writing is carried out using theprinter-side antenna 124 a, without it being in contact with the element75 a. It should be noted that when this writing is carried out, theblack developing unit 53 has not reached the detaching position (theattach/detach position) where it can be detached via the attach/detachopening 10 e.

<Step of Ending Printing Operation (Step 165)>

When the rotary 55 arrives at the home position, the image formingprocess is ended, and the printer enters the image forming processstandby state.

The process described above is only one example, and modifications tothe above may be made freely as long as the printer-side antenna 124 a,which serves as a writing member, can write information into the element75 a of the photoconductor unit 75 during the period from when adeveloping unit arrives at the opposing position (developing position)until it arrives at the detaching position (attach/detach position) dueto movement of the rotary 55.

In a configuration in which developing units having a developercontaining section can be attached to and detached from the developingunit attach/detach sections, there is a possibility that a developingunit attached to the developing unit attach/detach section mayinadvertently be detached via the attach/detach opening 10 e. Here, in aconfiguration in which the photoconductor unit 75 has the element 75 aand information related to the developing units is written to theelement 75 a, there is a possibility that the information stored in theelement 75 a will be incorrect if a developing unit is inadvertentlydetached via the attach/detach opening 10 e.

Here, with the foregoing image forming apparatus, information is writtento the element 75 a of the photoconductor unit 75 by the printer-sideantenna 124 a during the period from when the developing unit arrives atthe opposing position until when it arrives at the detaching positiondue to movement of the rotary 55, and thus even when the developing unitis inadvertently detached via the attach/detach opening 10 e, it ispossible to keep the reliability of the information stored in theelement 75 a from being impaired.

In particular, as described above, it is preferable that theprinter-side antenna 124 a writes information to the element 75 a of thephotoconductor unit 75 during the period from after developing of thelatent image by the developer bearing body provided in that developingunit that has arrived at the opposing position has ended until when thatdeveloping unit arrives at the detaching position.

The amount of developer in a developing unit decreases when the latentimage is developed by the developer bearing body provided in thatdeveloping unit. Here, with the foregoing image forming apparatus,information is written to the element 75 a of the photoconductor unit 75by the printer-side antenna 124 a during the period from afterdeveloping of the latent image by the developer bearing body provided inthat developing unit that has arrived at the opposing position has endeduntil when that developing unit arrives at the detaching position.Consequently, information about the remaining amount, for example, basedon the amount of developer that has been reduced by developing, and thenumber of sheets printed by each toner color, for example, can bewritten to the element 75 a of the photoconductor unit 75.

It is more preferable that the printer-side antenna 124 a writesinformation to the element 75 a of the photoconductor unit 75 during aperiod from when the developing unit starts moving from the opposingposition until when the developing unit arrives at the detachingposition due to movement of the rotary 55.

With this image forming apparatus, the time from when a developing unitstarts moving from the opposing position until it arrives at thedetaching position can be utilized to effectively write information.

Also, in the example described above, after the yellow developing unit54 began moving from the developing position, first, the yellowdeveloping unit 54 arrived at the attach/detach position where it can beattached and detached, and then when the rotary 55 rotated further, thecyan developing unit 51 upstream in the direction of rotation arrived atthe developing position. However, it is also possible that after theyellow developing unit 54 has begun moving from the developing position,the cyan developing unit 51 upstream in the direction of rotation firstarrives at the developing position, and then when the rotary 55 rotatesfurther, the yellow developing unit 54 arrives at the attach/detachposition where it can be attached and detached.

In this way, if, during the time that a developing unit starts movingfrom the developing position until it arrives at the attach/detachposition, another developing unit adjacent to said developing unit onthe upstream side in the rotating direction of the rotary arrives at thedeveloping position, then it is preferable that the printer-side antenna124 a writes information to the element 75 a of the photoconductor unit75 during a period until the other developing unit arrives at thedeveloping position. The printer-side antenna 124 a writes informationto the element 75 a of the photoconductor unit 75 until the time thatthe other developing unit arrives at the developing position, and thuseven if, for example, the developing unit is forcibly detached after theother developing unit arrives at the developing position, for example,information will have already been written to the element 75 a.

As described above, it is preferable that the printer-side antenna 124 awrites information to the element 75 a when the AC voltage supplysection 126 a is not supplying AC voltage to the developing roller 510.By writing information at this timing, information can be writtenaccurately without being affected by the noise caused by supplying ACvoltage to the developing roller 510, for example.

It should be noted that the information written into the element 75 a isnot limited to the foregoing example, and as shown in FIG. 8, it canalso be, for example, the number of printed sheets when usage starts,the number of printed sheets when usage ends, or the number of sheetsprinted in monochrome.

It may also be information about, for example, the remaining amount oftoner or the usage amount of toner of each of the developing units. Inthis case, for example, in place of the step of writing information tothe element of each of the developing units in FIG. 10, it is possibleto provide a step of writing information into the element 75 a of thephotoconductor unit 75.

Other Embodiments

In the foregoing, developing units, for example, according to thepresent invention were described based on an embodiment thereof.However, the foregoing embodiment of the invention is for the purpose ofelucidating the present invention and is not to be interpreted aslimiting the present invention. The invention can of course be alteredand improved without departing from the gist thereof and includesequivalents thereof.

<Printer-Side Antenna>

As long as the longitudinal direction of the printer-side antenna forwireless communication with the elements of the developing units is inthe direction of rotation of the rotary 55, the antenna may assume anyconfiguration. It should be noted that if the rotary 55 employed as themoving body moves rotatively, then the longitudinal direction of theprinter-side antenna being in the direction of movement of the movingbody means that the longitudinal direction of the printer-side antennais in a tangential direction at a position in opposition to theprinter-side antenna in the rotation radius of the rotary 55. FIG. 12 isa diagram showing a first alternative embodiment of the printer-sideantenna. In FIG. 12, a printer-side antenna 124 c is provided at aposition where it is in opposition to and extends over a firstdeveloping unit (the yellow developing unit 54) attached to a firstattach/detach section and a second developing unit (the black developingunit 53) attached to a second attach/detach section that is adjacent tothe first attach/detach section. Thus, wireless communication can becarried out more effectively with respect to the elements of thedeveloping units that are attached to the attach/detach sectionsprovided in the rotary 55. Also, in the example shown in FIG. 12, theprinter-side antenna 124 c is in opposition to a first element of thefirst developing unit (the element 54 a of the yellow developing unit54), but it is also possible for the printer-side antenna 124 c to be inopposition to a second element of the second developing unit (theelement 53 a of the black developing unit 53) as well.

It is also possible to adopt a configuration such as that shown in FIG.13 and FIG. 14. FIG. 13 is a diagram showing another embodimentregarding an arrangement for the elements. FIG. 14 is a diagram showinga second alternative embodiment of the printer-side antenna, and showsan arrangement seen from the inner side of the printer unit when theside of the printer unit 10 a on which the first open/close cover 10 bis provided is regarded as the front side.

In FIG. 13, the element 54 a is provided on a lateral surface of theyellow developing unit 54. This lateral surface is the lateral surfacethat becomes the front end side in the attaching direction when theyellow developing unit 54 is attached to the printer unit 10 a via theattach/detach opening 10 e. In correspondence with this provision of theelement 54 a on the lateral surface of the yellow developing unit 54, aprinter-side antenna 124 d is provided in opposition to the element 54a, as shown in FIG. 14. More specifically, the printer-side antenna 124d is provided more to the outside than the element 54 a in the directionof the rotation axis of the rotary 55, that is, more towards the inwarddirection of the printer unit 10 a than the element 54 a, without beingin contact with the element 54 a. Even with this arrangement, theprinter-side antenna 124 d, which is provided more to the outside thanthe element 54 a in the direction of the rotation axis of the rotary 55,can be used to effectively achieve wireless communication with respectto the elements of the developing units attached to the attach/detachsections provided in the rotary 55.

It is also possible for the length of the printer-side antenna in thelongitudinal direction to be shorter than the length of the element inthat longitudinal direction. However, as in the foregoing embodiment, aconfiguration in which the length of the printer-side antenna in thelongitudinal direction is longer than the length of the element in thatlongitudinal direction is advantageous in terms that it allows wirelesscommunication with respect to the elements of the developing unitsattached to the attach/detach sections provided in the moving body to beachieved more effectively.

<Moving Body>

The moving body is not limited to a rotary-type member that movesrotatively, and it may also be a member that carries out translationoperation.

<Another Example of AC Voltage Application>

It is also possible to adopt a configuration in which the AC voltagesupply section 126 a supplies an AC voltage to the charging unit 30 viathe charging unit drive circuit so that the charging unit 30 charges thephotoconductor 20 in an alternating electric field. In this case, duringthe period from the start to the end of the image forming process, theprinter-side antenna 124 b can write information into the element of thedeveloping unit attached to the attach/detach section when the ACvoltage supply section 126 a is not supplying an AC voltage to thecharging unit 30. Thus, information can be written accurately withoutbeing affected by, for example, noise caused by supplying the AC voltageto the charging unit 30.

It is also possible to adopt a configuration in which the AC voltagesupply section 126 a supplies an AC voltage to the first transferringunit 60 via the first transferring unit drive circuit. In this case,during the period from the start to the end of the image formingprocess, the printer-side antenna 124 b can write information into theelement of the developing unit attached to the attach/detach sectionwhen the AC voltage supply section 126 a is not supplying an AC voltageto the first transferring unit 60. Thus, information can be writtenaccurately without being affected by, for example, noise caused bysupplying the AC voltage to the first transferring unit 60.

<Intensity of the AC Voltage>

The present embodiment is particularly effective in image formingprocessing in which there is a large difference between the maximumvoltage value and the minimum voltage value applied by the AC voltagesupply section 126 a. For example, it is particularly effective in imageforming apparatuses in which the difference between the maximum voltagevalue and the minimum voltage value is 1000 volts or more. When thedifference between the maximum voltage value and the minimum voltagevalue of the AC voltage is 1000 volts or more, the electromagnetic noisethat occurs also becomes large. In such image forming apparatuses, bywriting information with the writing member into the element of adeveloping unit that is attached to the attach/detach section when theAC voltage supply section 126 a is not supplying an AC voltage duringthe period from the start to the end of the image forming process, itbecomes possible to accurately write information without being affectedby, for example, the large amount of noise that is caused by supplyingthe AC voltage.

<Developing Unit>

The developing unit is not limited to a device of the configurationdescribed in the foregoing embodiment, and it is applicable to any typeof developing unit. The developing unit may be of any configuration aslong as it has an element into which information can be written and adeveloper containing section. For example, the developing unit does nothave to include a developer bearing body, and the developing unit may beprovided in the printer unit 10 a.

For example, it is possible to use any material as the developer bearingroller, such as magnetic material, non-magnetic material, conductivematerial, insulating material, metal, rubber, and resin, as long as itis possible to structure a developer bearing roller. For example, as thematerial, it is possible to use: metal such as aluminum, nickel,stainless steel, and iron; rubber such as natural rubber, siliconerubber, urethane rubber, butadiene rubber, chloroprene rubber, neoprenerubber, and NBR; or resin such as styrene resin, vinyl chloride resin,polyurethane resin, polyethylene resin, methacrylate resin, and nylonresin. Further, it is without saying that these can be used even if theupper layer of these materials is coated. In this case, as the coatingmaterial, it is possible to use, for example, polyethylene, polystyrene,polyurethane, polyester, nylon, or acrylic resin. Further, it ispossible to use any form, such as an inelastic body, an elastic body, asingle-layer structure, a multi-layer structure, a film, and a roller.Further, the developer is not limited to toner, but it may be, forexample, a two component developer in which a carrier is mixed.

Further, the same applies for the toner supplying member as well, and asthe material therefor, other than polyurethane foam described above, itis possible to use, for example, polystyrene foam, polyethylene foam,polyester foam, ethylene propylene foam, nylon foam, or silicone foam.It should be noted that, as the foam cells of the toner supplying means,both open-cell foams and closed-cell foams can be used. It should benoted that there is no limitation to foam material, and it is possibleto use rubber material having elasticity. More specifically, it ispossible to use a material that is molded and in which a conductiveagent such as carbon is dispersed into, for example, silicone rubber,urethane rubber, natural rubber, isoprene rubber, styrene butadienerubber, butadiene rubber, chloroprene rubber, butyl rubber, ethylenepropylene rubber, epichlorohydrin rubber, nitrile butadiene rubber, oracrylic rubber.

<Photoconductor Unit>

The photoconductor unit 75 also is not limited to the device of theconfiguration described in the foregoing embodiment, and it isapplicable to any type of device. It is only necessary that the photoconductor unit 75 has an element into which information can be writtenand a photoconductor. For example, it does not have to include thecharging unit 30, and instead, the charging unit may be provided in theprinter unit 10 a. Further, the photoconductor is not limited to aroller-shaped photoconductive roller, and it may also be belt-shaped.

<Elements>

The elements of the developing units and the element of thephotoconductor unit are not limited to the configuration described inthe foregoing embodiment. It is only necessary that information can bewritten into them, and it is possible for them to be, for example,elements in which the antenna is provided separately.

<Image Forming Apparatus>

In the foregoing embodiment, an intermediate transferring typefull-color laser beam printer was described as an example of the imageforming apparatus, but the present invention is also applicable tovarious other types of image forming apparatuses, such as full-colorlaser beam printers that are not of the intermediate transferring type,monochrome laser beam printers, copying machines, and facsimiles.

===Configuration of Computer System Etc.===

Next, an embodiment of a computer system, a computer program, and astorage medium on which the computer program is recorded, which serve asan example of an embodiment of the present invention, is described withreference to the drawings.

FIG. 15 is an explanatory drawing showing an external structure of acomputer system. The computer system 1000 comprises a computer unit1102, a display device 1104, a printer 1106, an input device 1108, and areading device 1110. In this embodiment, the computer unit 1102 isaccommodated in a mini-tower type housing, but this is not a limitation.A CRT (cathode ray tube), a plasma display, or a liquid crystal displaydevice, for example, is generally used as the display device 1104, butthis is not a limitation. The printer described above is used as theprinter 1106. In this embodiment, a keyboard 1108A and a mouse 1108B areused as the input device 1108, but this is not a limitation. In thisembodiment, a flexible disk drive device 1110A and a CD-ROM drive device1110B are used as the reading device 1110, but the reading device is notlimited to these, and it may also be other devices such as a MO (magnetooptical) disk drive device and a DVD (digital versatile disk).

FIG. 16 is a block diagram showing a configuration of the computersystem shown in FIG. 15. Further provided are an internal memory 1202,such as a RAM inside the housing accommodating the computer unit 1102,and an external memory such as a hard disk drive unit 1204.

It should be noted that in the above description, an example in whichthe computer system is structured by connecting the printer 1106 to thecomputer unit 1102, the display device 1104, the input device 1108, andthe reading device 1110 was described, but this is not a limitation. Forexample, the computer system can be made of the computer unit 1102 andthe printer 1106, or the computer system does not have to comprise anyone of the display device 1104, the input device 1108, and the readingdevice 1110.

Further, for example, the printer 1106 can have some of the functions ormechanisms of the computer unit 1102, the display device 1104, the inputdevice 1108, and the reading device 1110. As an example, the printer1106 maybe configured so as to have an image processing section forcarrying out image processing, a displaying section for carrying outvarious types of displays, and a recording media attach/detach sectionto and from which recording media storing image data captured by adigital camera or the like are inserted and taken out.

As an overall system, the computer system that is achieved in this waybecomes superior to conventional systems.

INDUSTRIAL APPLICABILITY

According to a main aspect of the present invention, it is possible toachieve an image forming apparatus, a developing unit, and a computersystem with which accurate communication can be carried out with respectto developing units etc. having elements.

Also, according to another main aspect of the present invention, it ispossible to achieve an image forming apparatus and a computer systemwith which information can be accurately written into developing unitsetc. having elements.

1. An image forming apparatus comprising: a moving body provided with aplurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of said attach/detach sections,and said developing unit has a developer containing section and anelement with which communication is possible; a photoconductor on whicha latent image can be formed; and an antenna for wirelesslycommunicating with said element of the developing unit attached to theattach/detach section; wherein a longitudinal direction of said antennais in a direction of movement of said moving body.
 2. An image formingapparatus according to claim 1, wherein said moving body movesrotatively.
 3. An image forming apparatus according to claim 2, whereinsaid antenna is provided more to the outside than said element in aradial direction of rotation of said moving body.
 4. An image formingapparatus according to claim 2, wherein said antenna is provided more tothe outside than said element in a direction of a rotation axis of saidmoving body.
 5. An image forming apparatus according to claim 1, whereinsaid antenna is capable of wirelessly communicating with said element ofthe developing unit that is moving.
 6. An image forming apparatusaccording to claim 1, wherein said antenna is capable of communicatingwith said element in a non-contact state with respect to said element.7. An image forming apparatus according to claim 1, wherein said antennais used to write, into said element, information indicating a remainingamount of developer contained in the developing unit provided with thatelement.
 8. An image forming apparatus according to claim 1, whereinsaid antenna writes, into said element, information indicating a usageamount of developer contained in the developing unit provided with thatelement.
 9. An image forming apparatus comprising: a moving bodyprovided with a plurality of attach/detach sections, wherein adeveloping unit is attachable to and detachable from each of saidattach/detach sections, and said developing unit has developercontaining section and element with which communication is possible; aphotoconductor on which a latent image can be formed; and an antenna forwirelessly communicating with said element of the developing unitattached to the attach/detach section; wherein a longitudinal directionof said antenna is in a direction of movement of said moving body; andwherein a length of said antenna in said longitudinal direction islonger than a length of said element in said longitudinal direction. 10.An image forming apparatus comprising: a moving body provided with aplurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of said attach/detach sections,and said developing unit has a developer containing and an element withwhich communication is possible; a photoconductor on which a latentimage can be formed; and an antenna for wirelessly communicating withsaid element of the developing unit attached to the attach/detachsection; wherein a longitudinal direction of said antenna is in adirection of movement of said moving body; and wherein said antenna isprovided at a position that is in opposition to and extending over afirst developing unit attached to a first attach/detach section and asecond developing unit attached to a second attach/detach section thatis adjacent to said first attach/detach section.
 11. An image formingapparatus according to claim 10, wherein said antenna is provided at aposition that is in opposition to at least either one of a first elementprovided in/on said first developing unit or a second element providedin/on said second developing unit.
 12. An image forming apparatuscomprising: a moving body provided with a plurality of attach/detachsections, wherein a developing unit is attachable to and detachable fromeach of said attach/detach sections, and said developing unit has adeveloper containing section and an element with which communication ispossible; a photoconductor on which a latent image can be formed; and anantenna for wirelessly communicating with said element of the developingunit attached to the attach/detach section; wherein a longitudinaldirection of said antenna is in a direction of movement of said movingbody; wherein said antenna is capable of wirelessly communicating withsaid element of the developing unit that is moving; and wherein saidantenna is used to write information wirelessly into said element of thedeveloping unit that is moving.
 13. An image forming apparatuscomprising: a moving body provided with a plurality of attach/detachsections, wherein a developing unit is attachable to and detachable fromeach of said attach/detach sections, and said developing unit has adeveloper containing section and an element with which communication ispossible; a photoconductor on which a latent image can be formed; and anantenna for wirelessly communicating with said element of the developingunit attached to the attach/detach section; wherein a longitudinaldirection of said antenna is in a direction of movement of said movingbody; wherein said image forming apparatus comprises an AC voltagesupply section for supplying an AC voltage; and wherein during a periodfrom a start to an end of an image forming process, said image formingapparatus writes information into said element of the developing unitattached to said attach/detach section using said antenna when said ACvoltage supply section is not supplying an AC voltage.
 14. An imageforming apparatus according to claim 13, wherein: said developing unithas a developer bearing body for bearing developer; and said AC voltagesupply section supplies an AC voltage to said developer bearing body.15. An image forming apparatus according to claim 13, wherein: saidimage forming apparatus comprises a charging member for charging saidphotoconductor; and said AC voltage supply section supplies an ACvoltage to said charging member.
 16. An image forming apparatusaccording to claim 13, wherein a difference between a maximum voltagevalue and a minimum voltage value of said AC voltage is 1000 volts ormore.
 17. An image forming apparatus comprising: a moving body providedwith a plurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of said attach/detach sections,and said developing unit has a developer containing section and anelement with which communication is possible; a photoconductor on whicha latent image can be formed; and an antenna for wirelesslycommunicating with said element of the developing unit attached to theattach/detach section; wherein a longitudinal direction of said antennais in a direction of movement of said moving body; wherein said imageforming apparatus comprises an attach/detach opening through which saiddeveloping unit is attached to and detached from said attach/detachsection; wherein in a state in which said developing unit is positionedat an opposing position where said developing unit is in opposition tosaid photoconductor due to movement of said moving body, development ofsaid latent image with the developer contained in said developing unitis possible; wherein in a state in which said developing unit ispositioned at a detaching position that is different from said opposingposition due to movement of said moving body, detachment of saiddeveloping unit from said attach/detach section via said attach/detachopening is possible; and wherein during a period from when saiddeveloping unit arrives at said opposing position until when saiddeveloping unit arrives at said detaching position due to movement ofsaid moving body, said image forming apparatus writes information intosaid element of said developing unit using said antenna.
 18. An imageforming apparatus comprising: a moving body provided with a plurality ofattach/detach sections, wherein a developing unit is attachable to anddetachable from each of said attach/detach sections, and said developingunit has a developer containing section and an element with whichcommunication is possible; a photoconductor on which a latent image canbe formed; and an antenna for wirelessly communicating with said elementof the developing unit attached to the attach/detach section, wherein: alongitudinal direction of said antenna is in a direction of movement ofsaid moving body; said moving body moves rotatively; a length of saidantenna in said longitudinal direction is longer than a length of saidelement in said longitudinal direction; said antenna is provided at aposition that is in opposition to and extending over a first developingunit attached to a first attach/detach section and a second developingunit attached to a second attach/detach section that is adjacent to saidfirst attach/detach section; said antenna is provided at a position thatis in opposition to at least either one of a first element providedin/on said first developing unit or a second element provided in/on saidsecond developing unit; said antenna is capable of wirelesslycommunicating with said element of the developing unit that is moving;said antenna is capable of communicating with said element in anon-contact state with respect to said element; and said antenna is usedto write, into said element, information indicating a remaining amountor a usage amount of developer contained in the developing unit providedwith that element.
 19. A developing unit comprising: a developercontaining section; and an element with which communication is possible,wherein: said developing unit is capable of being attached to anddetached from an attach/detach section of a main body of an imageforming apparatus that includes: a moving body provided with a pluralityof the attach/detach sections, said developing unit being attachable toand detachable from one of said attach/detach sections; a photoconductoron which a latent image can be formed; and an antenna for wirelesslycommunicating with said element of the developing unit attached to theattach/detach section; and a longitudinal direction of said element isin a longitudinal direction of said antenna when said developing unit isattached to said attach/detach section.
 20. A developing unit accordingto claim 19, wherein said developing unit is capable of being attachedto said attach/detach section of said moving body which movesrotatively.
 21. A developing unit according to claim 19, wherein saidelement is capable of communicating with said antenna in a non-contactstate with respect to said antenna.
 22. A developing unit according toclaim 19, wherein said element stores information indicating a remainingamount of developer contained in the developing unit provided with thatelement.
 23. A developing unit according to claim 19, wherein saidelement stores information indicating a usage amount of developercontained in the developing unit provided with that element.
 24. Adeveloping unit comprising: a developer containing section; and anelement with which communication is possible, wherein said developingunit is capable of being attached to and detached from an attach/detachsection of a main body of an image forming apparatus that includes: amoving body provided with a plurality of the attach/detach sections,said developing unit being attachable to and detachable from one of saidattach/detach sections; a photoconductor on which a latent image can beformed; and an antenna for wirelessly communicating with said element ofthe developing unit attached to the attach/detach section; wherein alongitudinal direction of said element is in a longitudinal direction ofsaid antenna when said developing unit is attached to said attach/detachsection; and wherein a length of said element in said longitudinaldirection is shorter than a length of said antenna in said longitudinaldirection.
 25. A computer system comprising: a computer unit; and animage forming apparatus that is connected to said computer unit and thatincludes a moving body provided with a plurality of attach/detachsections, wherein a developing unit is attachable to and detachable fromeach of said attach/detach sections, and said developing unit has adeveloper containing section and an element with which communication ispossible, a photoconductor on which a latent image can be formed, and anantenna for wirelessly communicating with said element of the developingunit attached to the attach/detach section, wherein a longitudinaldirection of said antenna is in a direction of movement of said movingbody.
 26. An image forming apparatus comprising: a moving body providedwith a plurality of attach/detach sections, wherein a developing unit isattachable to and detachable from each of said attach/detach sections,and said developing unit has a developer containing section and anelement into which information can be written; a photoconductor on whicha latent image can be formed; a writing member for writing informationinto said element; and an attach/detach opening through which saiddeveloping unit is attached to and detached from the attach/detachsection, wherein: in a state in which said developing unit is positionedat an opposing position where said developing unit is in opposition tosaid photoconductor due to movement of said moving body, development ofsaid latent image with the developer contained in said developing unitis possible; in a state in which said developing unit is positioned at adetaching position that is different from said opposing position due tomovement of said moving body, detachment of said developing unit fromsaid attach/detach section via said attach/detach opening is possible;and during a period from when said developing unit arrives at saidopposing position until when said developing unit arrives at saiddetaching position due to movement of said moving body, said writingmember writes information into said element of said developing unit. 27.An image forming apparatus according to claim 26, wherein during aperiod from when a developer bearing body provided in the developingunit that has arrived at said opposing position ends developing saidlatent image until when said developing unit arrives at said detachingposition, said writing member writes information into said element ofsaid developing unit.
 28. An image forming apparatus according to claim27, wherein during a period from when said developing unit starts movingfrom said opposing position until when said developing unit arrives atsaid detaching position due to movement of said moving body, saidwriting member writes information into said element of said developingunit.
 29. An image forming apparatus according to claim 26, wherein if,during the period from when said developing unit starts moving from saidopposing position until when said developing unit arrives at saiddetaching position, another developing unit adjacent to said developingunit on the upstream side therefrom in a direction of movement of saidmoving body is to arrive at said opposing position, then said writingmember writes information into said element of said developing unitduring a period until said other developing unit arrives at saidopposing position.
 30. An image forming apparatus according to claim 26,wherein: said image forming apparatus comprises an AC voltage supplysection for supplying an AC voltage; and said writing member writesinformation into said element of the developing unit attached to saidattach/detach section when said AC voltage supply section is notsupplying an AC voltage.
 31. An image forming apparatus according toclaim 30, wherein: said developing unit has a developer bearing body forbearing developer; and said AC voltage supply section supplies an ACvoltage to said developer body.
 32. An image forming apparatus accordingto claim 30, wherein: said image forming apparatus comprises a chargingmember for charging said photoconductor; and said AC voltage supplysection supplies an AC voltage to said charging member.
 33. An imageforming apparatus according to claim 30, wherein a difference between amaximum voltage value and a minimum voltage value of said AC voltage is1000 volts or more.
 34. An image forming apparatus according to claim26, wherein said writing member writes information into said element ina non-contact state with respect to said element.
 35. An image formingapparatus according to claim 26, wherein said writing member writes,into said element, information indicating a remaining amount ofdeveloper contained in the developing unit provided with said element.36. An image forming apparatus according to claim 26, wherein saidwriting member writes, into said element, information indicating a usageamount of developer contained in the developing unit provided with saidelement.
 37. An image forming apparatus comprising: a moving bodyprovided with a plurality of attach/detach sections, wherein adeveloping unit is attachable to and detachable from each of saidattach/detach sections, and said developing unit has a developercontaining section and an element into which information can be written;a photoconductor on which a latent image can be formed; a writing memberfor writing information into said element; and an attach/detach openingthrough which said developing unit is attached to and detached from theattach/detach section, wherein: in a state in which said developing unitis positioned at an opposing position where said developing unit is inopposition to said photoconductor due to movement of said moving body,development of said latent image with the developer contained in saiddeveloping unit is possible; in a state in which said developing unit ispositioned at a detaching position that is different from said opposingposition due to movement of said moving body, detachment of saiddeveloping unit from said attach/detach section via said attach/detachopening is possible; during a period from when said developing unitstarts moving from said opposing position until when said developingunit arrives at said detaching position due to movement of said movingbody, said writing member writes information into said element of saiddeveloping unit; if, during the period from when said developing unitstarts moving from said opposing position until when said developingunit arrives at said detaching position, another developing unitadjacent to said developing unit on the upstream side therefrom in adirection of movement of said moving body is to arrive at said opposingposition, then said writing member writes information into said elementof said developing unit during a period until said other developing unitarrives at said opposing position; said developing unit has a developerbearing body for bearing developer; said image forming apparatuscomprises an AC voltage supply section for supplying an AC voltage; saidAC voltage supply section supplies an AC voltage to said developerbearing body; said writing member writes information into said elementof the developing unit attached to said attach/detach section when saidAC voltage supply section is not supplying an AC voltage to saiddeveloper bearing body; said writing member writes information into saidelement in a non-contact state with respect to said element; adifference between a maximum voltage value and a minimum voltage valueof said AC voltage is 1000 volts or more; and said writing memberwrites, into said element, information indicating a remaining amount ora usage amount of developer contained in the developing unit providedwith said element.
 38. An image forming apparatus comprising: a movingbody provided with a plurality of developing unit attach/detachsections, wherein a developing unit having a developer containingsection is attachable to and detachable from each of said developingunit attach/detach sections; a photoconductor unit attach/detach sectionto and from which a photoconductor unit can be attached and detached,wherein said photoconductor unit has a photoconductor and an elementinto which information can be written; a writing member for writinginformation into said element; and an attach/detach opening throughwhich said developing unit is attached to and detached from theattach/detach section, wherein: in a state in which said developing unitis positioned at an opposing position where said developing unit is inopposition to said photoconductor due to movement of said moving body,development of a latent image formed on said photoconductor with thedeveloper contained in said developing unit is possible; in a state inwhich said developing unit is positioned at a detaching position that isdifferent from said opposing position due to movement of said movingbody, detachment of said developing unit from said developing unitattach/detach section via said attach/detach opening is possible; andduring a period from when said developing unit arrives at said opposingposition until when said developing unit arrives at said detachingposition due to movement of said moving body, said writing member writesinformation into said element of said photoconductor unit.
 39. An imageforming apparatus according to claim 38, wherein during a period fromwhen a developer bearing body provided in the developing unit that hasarrived at said opposing position ends developing said latent imageuntil when said developing unit arrives at said detaching position, saidwriting member writes information into said element of saidphotoconductor unit.
 40. An image forming apparatus according to claim39, wherein during a period from when said developing unit starts movingfrom said opposing position until when said developing unit arrives atsaid detaching position due to movement of said moving body, saidwriting member writes information into said element of saidphotoconductor unit.
 41. An image forming apparatus according to claim38, wherein if, during the period from when said developing unit startsmoving from said opposing position until when said developing unitarrives at said detaching position, another developing unit adjacent tosaid developing unit on the upstream side therefrom in a direction ofmovement of said moving body is to arrive at said opposing position,then said writing member writes information into said element of saidphotoconductor unit during a period until said other developing unitarrives at said opposing position.
 42. An image forming apparatusaccording to claim 38, wherein: said image forming apparatus comprisesan AC voltage supply section for supplying an AC voltage; and saidwriting member writes information into said element of saidphotoconductor unit attached to said photoconductor unit attach/detachsection when said AC voltage supply section is not supplying an ACvoltage.
 43. An image forming apparatus according to claim 42, wherein:said developing unit has a developer bearing body for bearing developer;and said AC voltage supply section supplies an AC voltage to saiddeveloper bearing body.
 44. An image forming apparatus according toclaim 42, wherein: said image forming apparatus comprises a chargingmember for charging said photoconductor; and said AC voltage supplysection supplies an AC voltage to said charging member.
 45. An imageforming apparatus according to claim 42, wherein a difference between amaximum voltage value and a minimum voltage value of said AC voltage is1000 volts or more.
 46. An image forming apparatus according to claim38, wherein said writing member writes information into said element ina non-contact state with respect to said element.
 47. An image formingapparatus according to claim 38, wherein said writing member writes,into said element, information indicating a remaining amount ofdeveloper contained in the developing unit.
 48. An image formingapparatus according to claim 38, wherein said writing member writes,into said element, information indicating a usage amount of developercontained in the developing unit provided with said element.
 49. Acomputer system comprising: a computer unit; and an image formingapparatus that is connected to said computer unit and that includes amoving body provided with a plurality of attach/detach sections, whereina developing unit is attachable to and detachable from each of saidattach/detach sections, and said developing unit has a developercontaining section and an element into which information can be written;a photoconductor on which a latent image can be formed; a writing memberfor writing information into said element; and an attach/detach openingthrough which said developing unit is attached to and detached from theattach/detach section; wherein, in a state in which said developing unitis positioned at an opposing position where said developing unit is inopposition to said photoconductor due to movement of said moving body,development of said latent image with the developer contained in saiddeveloping unit is possible; and wherein, in a state in which saiddeveloping unit is positioned at a detaching position that is differentfrom said opposing position due to movement of said moving body,detachment of said developing unit from said attach/detach section viasaid attach/detach opening is possible; wherein, during a period fromwhen said developing unit arrives at said opposing position until whensaid developing unit arrives at said detaching position due to movementof said moving body, said writing member writes information into saidelement of said developing unit.
 50. A computer system comprising: acomputer unit; and an image forming apparatus that is connected to saidcomputer unit and that includes a moving body provided with a pluralityof developing unit attach/detach sections, wherein a developing unithaving a developer containing section is attachable to and detachablefrom each of said developing unit attach/detach sections; aphotoconductor unit attach/detach section to and from which aphotoconductor unit can be attached and detached, wherein saidphotoconductor unit has a photoconductor and an element into whichinformation can be written; a writing member for writing informationinto said element; and an attach/detach opening through which saiddeveloping unit is attached to and detached from the attach/detachsection; wherein, in a state in which said developing unit is positionedat an opposing position where said developing unit is in opposition tosaid photoconductor due to movement of said moving body, development ofa latent image formed on said photoconductor with the developercontained in said developing unit is possible; and wherein, in a statein which said developing unit is positioned at a detaching position thatis different from said opposing position due to movement of said movingbody, detachment of said developing unit from said developing unitattach/detach section via said attach/detach opening is possible;wherein, during a period from when said developing unit arrives at saidopposing position until when said developing unit arrives at saiddetaching position due to movement of said moving body, said writingmember writes information into said element of said photoconductor unit.